Perfect Score Chemistry SBP 2012 - Module

BAHAGIAN BAHAGIAN PENGURUSAN PEN GURUSAN SEKOLAH BERASRAMA PENUH DAN SEKOLAH KECEMERLANGA K ECEMERLANGAN N

MODUL PERFECT SCORE &

 X A-PLUS  SEKOLAH BERASRAMA PENUH TAHUN 2012

PANEL PENYEDIA DAN PEMURNI: Pn. Wan Noor Afifah Binti Wan Yusoff (Ketua) Tn Hj Ja'afar B Bajuri Pn. Norini Binti Jaafar Tn Hj Che Malik Bin Mamat Pn. Rossita Binti Radzak En Jong Kak Ying En Ooi Yoong Seang Che Ramli B Che Ismail Pn Masodiah Bt Mahfodz Pn. Noraini Binti Zakaria

Chemistry Perfect Score Module 2012

SBPI GOMBAK  SMS SULTAN MAHMUD SEKOLAH SULTAN ALAM SHAH SBPI BATU RAKIT SMS TUANKU MUNAWIR  SMS KUCHING SMS MUAR  SMS FARIS PETRA SMS HULU SELANGOR  SMS SULTAN MOHAMAD JIWA

1

CHEMISTRY PERFECT SCORE MODULE 2012 CONTENT 

1

Guidelines &  Anwering Techniques Techniques

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2

Set 1

3

Set 2

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4

Set 3

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5

Set 4

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6

Set 5

Chemistry Perfect Score Module 2012

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Format of an instrument of chemistry Construct requirement Guidelines for answering paper 1 Guidelines for answering paper 2 Guidelines for answering paper 3 The common command words in paper 2

The structure of Atom Chemical Formulae and equations Periodic Table of Elements Chemical Bonds

Electrochemistry Oxidation and Reduction

Acids and Bases Salts Rate of reaction Thermochemistry

Carbon compounds Manufactured Manufactured Substance in Industry Chemicals for Consumers Paper 3 set 1 Paper 3 set 2 Paper 3 set 3

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CHEMISTRY PERFECT SCORE MODULE 2012 CONTENT 

1

Guidelines &  Anwering Techniques Techniques

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2

Set 1

3

Set 2

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4

Set 3

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5

Set 4

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6

Set 5

Chemistry Perfect Score Module 2012

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Format of an instrument of chemistry Construct requirement Guidelines for answering paper 1 Guidelines for answering paper 2 Guidelines for answering paper 3 The common command words in paper 2

The structure of Atom Chemical Formulae and equations Periodic Table of Elements Chemical Bonds

Electrochemistry Oxidation and Reduction

Acids and Bases Salts Rate of reaction Thermochemistry

Carbon compounds Manufactured Manufactured Substance in Industry Chemicals for Consumers Paper 3 set 1 Paper 3 set 2 Paper 3 set 3

2

CHEMISTRY PERFECT SCORE MODULE

GUIDELINES ANSWERING TECHNIQUES

CHEMISTRY SPM

Chemistry Perfect Score Module 2012

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GUIDELINES AND ANSWERING TECHNIQUES FOR SPM CHEMISTRY PAPER  1.0

FORMAT OF AN INSTRUMENT OF CHEMISTRY BEGINNING SPM 2003

 No

Item

1

Type of instrument Type of item

Paper 1 (4541/1) Objective test Objective it

2

3

 Number of  question

50 (answers all)

Duration of time

1 hour 15 minutes

5

2.0

Paper 2 (4541/2) Subjective test Section A : Structured Item Section B : Essay restricted response Item Section C : Essay extended response Item Section A : 6 (answer all) Section B : 2 (choose one) Section C : 2 (choose one) 2 hour 30 minutes

Paper 3 (4541/3) Written Practical Test Subjective Item : Structured Item Extended Response Item: (Planning an experiment)

Structured Item : 1/2 items (answer all) Extended Response Item : 1 item 1 hour 30 minutes

CONSTRUCT REQUIREMENT

Construct Knowledge Understanding Application Analysis Synthesizing Science process Total mark

Paper 1 20 m ( No 1- 20) 15 m ( No 21 – 35) 15 m ( No 36 – 50) 50

Paper 2 14 21 29 21 15 100

Paper 3 50 50

3.0 TIPS TO SCORE “ A “ CHEMISTRY

3.1

Master the topics that contains the basic concepts of chemistry : 1. The structure of the atom 2. Chemical Formulae And Equations 3. Periodic Table 4. Chemical Bond

3.2

Familiarize with different types of questions as listed below and complete the previous SPM  papers: 1. Objectives questions (MCQ) (Paper 1) 2. Structured questions ( Paper 2 & 3) 3. Essays (Paper 2) 4. Planning an experiment ( Paper 3) 5. Draw and label the diagram 6. Writing chemical equation( balanced equation, ionic equation, half equation)

3.3

Try to get : 40 marks above for paper 1  60 marks above for paper 2  40 marks above for paper 3

Chemistry Perfect Score Module 2012

(Total = 180/2 =80 , A+ in SPM)

4

4.0

GUIDELINE FOR ANSWERING PAPER 1

4.1

Paper 1 questions test students on 1. Knowledge ( Number 1 – 20) 2. Understanding ( Number 21 – 35) 3. Application ( Number 36 – 50 )

4.2

Score in paper 1 Indicates student’s level of understanding in chemistry: Less than 20 – very weak  20 – 25 - weak  26 – 30 - average 31 – 39 - good 40 – 45 - very good 46 – 50 - excellent.

4.3

Answer all SPM objective questions (2003  – 2010). Objective questions for each year contain all topics. If your score in paper 1 is 40 and above, you will able to answer questions in paper 2 & 3 easily.

5.0

GUIDELINE FOR ANSWERING PAPER 2 (STRUCTURE AND ESSAY) 5.1 Paper 2 questions test student on 1. Knowledge 2. understanding 3. analyzing 4. synthesizing 5.2 Steps taken are: 1. Underline the command word and marks allocated for each question. 2. Match the command word to the mark  allocated for each question. 1 point is awarded 1 mark. 3. Follow the needs of the question (Refer to the command words, page …….) 4. Unnecessary repetition of the statement in the question is not required. 5.3 Three types of questions which involve experiments in paper 2: I. Type 1 Describe an experiment on…………………Include a labeled diagram in your answer  1. Diagram 2. Procedure 3. Observation/example/data/calculation/equation/sketch of graph/conclusion II. Type 2 Describe an experiment……………( The diagram will support your answer.) 1.  No mark is allocated for a diagram 2. Procedures 3. Observation/example/calculation/equation/sketch of graph/conclusion III. Type 3 Describe a chemical/confirmatory test for ……. 1. Procedure 2. Observation 3. Conclusion

6.0

GUIDELINE FOR ANSWERING PAPER 3 6.1 Structure Question 1/2 test the mastery of 11 Scientific Skills 1. Observing 2. Classifying 3. Inferring 4. Measuring (burette , stopwatch, thermometer, voltmeter) 5. Predicting 6. Communicating( e.g construct table and draw graph) 7. Space-Time Relationship 8. Interpreting Data

Chemistry Perfect Score Module 2012

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9. Defining Operationally 10. Controlling Variables 11. Hypothesizing Each answer is allocated mark as follows: 3 marks/2 marks/1 mark/0

Score : 11 X 3 = 33

Example of operational definition: 1. what you do 2. what you observe correctly Example: 1. When acid is added into latex, white solid is formed. When acid is added into latex, latex coagulated.- wrong 2. When the higher the concentration sodium thiosulphate solution is added into sulphuric acid, time taken for  `X~ mark to disappear from sight is shorter. 3. When iron nail is coiled with copper and immersed into jelly mixed with potassium hexacyanoferrate(III) and  phenolphthalein solution, blue spot/colouration is formed. Operational definition for 1. Rusting of iron

2. Coagulation of latex 3. Reactivity of Group 1 elements 4. Precipitation of silver  chloride 5. Voltaic cell 6. An acid

What you do When an iron nail coiled with a less electropositive metal is immersed in hot agar-agar added with potassium hexacyanoferrate (III) solution, When acid is added to latex When a metal which is lower in Group 1 is  put in a basin half filled with water  When silver nitrate solution is added to sodium chloride solution When two different metals are dipped into an electrolyte When a blue litmus paper is dipped into a substance which is dissolved in water,

What is observed Blue spots are formed

White solid is formed Brighter flame is formed White solid is formed The needle of the voltmeter  deflects Blue litmus paper turns red

Hypothesis: Relate manipulated variable followed by responding variable with direction. Example: 1. The higher temperature of the reactant the higher the rate of reaction – 3 marks The temperature of the reactant affect the rate of reaction  – 2 marks 2. Hexene decolourised brown bromine water but hexane does not decolourised brown bromine water. 3. When acid is added into latex, latex coagulates, when ammonia is added into latex, latex cannot coagulates 4. Question 3 (essay) Test The Mastery of Planning Experiment . Planning should include the following aspects: 1. Aim of the experiment/Statement of the problem 2. All the variables 3. Statement of the hypothesis 4. List of substances/material and apparatus – should be separated 5. Procedure of the experiment 6. Score : (5 X 3) + 2 = 17 Tabulation of data

The question normally starts with certain situation related to daily life. Problem statement/ aim of the experiment / hypothesis and variable can be concluded from the situation given. State all the variables Manipulated variable : Responding variable : Constant variable: list down all the fixed variables to ensure the outcome of the responding variable is related only to the manipulated variables.

Chemistry Perfect Score Module 2012

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Separate the substances and apparatus - Separate the substances and apparatus - Apparatus : list down the apparatus for the experiment. Example: Rate of reaction – stop watch Termochemistry - thermometer  Procedure : All the steps taken in the procedure must include the apparatus used, quantity and type of substance (powder, solution, lumps … etc).  No mark is allocated for the diagram. The complete labeled diagram can help students in : I. Writing the steps taken in the procedure II. Listing the apparatus and materials Tabulation of data:   

7.0   

The number of columns and rows in the table is related to the manipulated and responding variables Units must be written for all the titles in each row and column of the table DO NOT WRITE the observation/inference/conclusion in the table.

THE COMMON COMMAND WORDS IN PAPER 2 & PAPER 3 CHEMISTRY The question normally starts with a command word. Students must know the meaning of the command word to make sure that the answer given is according to the question’s requirement. Match the command word to the mark allocated for each question.

Command word

 Name/State the name (paper 2 & 3) State (paper 2 & 3)

State the observation (Paper 2 & 3)

Explain (Paper 2 & 3)

What is meant by.. (Definition) (Paper 2 & 3) Describe chemical test (Paper 2 & 3)

Explanation/example

Give the name , not the formula. Example: Name the main element added to copper to form bronze. Wrong answer : Sn. Correct answer : Tin Give brief answer only. Explanation is not required. Example : State one substance which can conduct electricity in solid state. Answer : Copper  Write what is observed physically. Ex ample 1 : State one observation when magnesium powder is added to hydrochloric acid. [ 1 mark ] Wr ong an swer  : Hydrogen gas is released. Cor r ect answer : Gas bubbles are released Indicate the change of colour , give the initial and final colour of the substance/chemical. : What is the colour change of copper(II) suphate solution. [2 marks] Ex ample 2  : The solution becomes colourless Wr ong an swer  Cor r ect answer : The blue colour of the solution becomes colourless Give the answer with reasons to explain certain statement / fact / observation/ principal. Ex ample 1 : Explain why bronze is harder than pure copper [4 marks] Cor r ect answer : - Copper atoms in pure copper are all of the same size and ...........1 they are arranged in layers that can slide easily when force is applied ...........1 - The presence of tin atoms in bronze that are dif ferent in size disturb the orderly arrangement of atoms in bronze. ...........1 - This reduces the layer of atoms from sliding. ...........1 Give the exact meaning Example:  What is meant by hydrocarbon. Wr ong answer:  A compound that contains carbon and hydrogen : A compound that contains carbon hydrogen only Cor r ect answer  State the method to conduct the test , observation and conclusion. [3 marks] Example : Describe how to identify the ion present in the solution . 3 Answer : - Pour in 2 cm of the solution in a test tube. Add a few drops of sodium hydroxide solution and the test tube is shake the test tube ...........1

Chemistry Perfect Score Module 2012

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Describe gas test. (Paper 2 & 3)

- A reddish brown precipitate formed. ...........1 3+ - Fe ions present ………1 State the method to conduct the test observation and conclusion . Example: Describe the confirmatory test for gas released at the anode (oxygen). [3 marks] Wr ong an swer  : Test with a glowing wooden splinter. ..…….1 Cor r ect answer:  - Place a glowing wooden splinter to the mouth of the test tube - The glowing wooden splinter is lighted up ...……1 - Oxygen gas is released ..…….1 -

Describe an experiment ( 8 - 10 marks) (Paper 2)

Plan an experiment ( 17 marks) ( Paper 3)

Describe the process … Describe the structure …. Describe and write equation… Describe how … (Paper 2 & 3)

Predict (Paper 2 & 3) Compare (Paper 2) Differentiate (Paper 2) Draw a labeled diagram of the apparatus (Paper 2)

Draw a diagram to show the  bonding formed in the compound (Paper 2)

 No mark is awarded for the diagram. The diagram can help students write the steps taken in the procedure. - List of materials 1m Can be obtained from the diagram - List of apparatus 1m - Procedure ( 5 – 8 m) - Observation/tabulation of data/ calculation/sketch of the graph/ chemical equation /ionic equation /conclusion …… etc. - Any additional details relevant derived f rom the question. Answer the question according the requirement : Problem statement/Aim of experiment  Hyphotesis   Variables List of substances and apparatus   Procedure Tabulation of data   Note: For question 3, unlike PEKA report students only need to answer according to what is stated in the question. - No mark for the diagram. Diagram can help student writing the steps taken in the  procedure.

Give relevant details derived from the question.

Make a prediction for something that might happen based on facts  Example: Experiment 1 is repeated using a larger beaker. Predict the increase in temperature Answer : The increase in temperature is lower than experiment 1 . Give the similarities and differences between two items/ situations Give differences between two items/situations Example : State three differences between ionic and covalent compound. Answer : State three properties of ionic compound and three properties covalent compo und Draw a complete set up of apparatus (i) Functional set up of apparatus (ii) Complete label (iii) Shade solid, liquid and gas correctly. (iv) Draw an arrow and label ’ heat’ if the experiment involves heating (i) Ionic compound  – The number of electrons in each shell is correct, 2 electrons in the first shell and 8 electrons in the second and third shell.  – Show the charge of each particle.  – Write the symbol of each element at the centre of the ion. (ii) Covalent compound  The number of electrons in each shell is correct, 2 electrons in the first shell and 8 electrons in the second and third shell. The number of atoms sharing pair of electrons is correct. 

Chemistry Perfect Score Module 2012

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Write the symbol of each element at the center of each atom in the molecule. Draw graph as follows : Label the two axis with the correct unit   Choose suitable scale, the size of the graph should be at least ¾ of the size of the graph paper.  Plot all the points correctly  Smooth graph ( curve or straight line ) For the determination of the rate of reaction  (i) Draw a tangent at the curve. (ii) Draw a triangle at the tangent Calculate the gradient of the tangent  Draw an arrow for the vertical axis only and label with energy. Draw two horizontal lines for the reactants and products  

Draw graph (Paper 3)

Draw the energy level diagram ( Paper 2) Draw the arrangement of   particles in solid, liquid and gas. (Paper 2) Draw the direction of electron flow (Paper 2 /3) Write chemical equation (Paper 2 & 3)

Calculate (Paper 2 & 3) Classify (Paper 3)

  

Solid: Draw at least three layers of particles closely packed in orderly manner and they are not overlap. Liquid : The particles packed closely but not in orderly manner  Gas : The particles are very far apart from each other 

Draw the direction for the flow of electrons on the circuit, not through the solution.  

  

Write the balanced chemical equation Differentiate : (i) Balanced chemical equation (ii) Ionic equation (iii) Half equation for oxidation (iv) Half equation for reduction Show all the steps taken Give final answer with unit. Draw table to represent the classification.

Chemistry Perfect Score Module 2012

9

CHEMISTRY MODULE

SET



1. The Structure of Atom 2. Chemical Formulae and Equations 3. Periodic Table of Elements 4. Chemical Bonds

Chemistry Perfect Score/ X A- Plus Module 2012

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SECTION A 1. Table 1 shows the proton number and nucleon number for atoms L, M and N. Atom

Proton number

Nucleon number

L

16

32

M

17

35

 N

17

37 Table 1

(a)

(i) What is meant by proton number ? ……………………………………………………………………………………… [1 mark ] (ii) What is the number of neutrons in atom M ?

(b)

……………………………………………………………………………………… [1 mark ] Which atoms are isotopes ? Explain your answer. ……………………………………………………………………………………… ……………………………………………………………………………………… [2 marks]

(c)

(i) Write the electron arrangement for atom L. ……………………………………………………………………………………… [1 mark ] (ii) State the position of atom L in the Periodic Table ………………………………………………………………………………… [1 mark ] (iii) Explain your answer in c (ii) …………………………………………………………………………………..

(d)

……………………………………………………………………………………. [2 marks ] Write the formula of ion formed from atom M ……………………………………………………………………………………… [1 mark ]

Chemistry Perfect Score/ X A- Plus Module 2012

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2

Diagram 2 shows part of the Periodic Table of Elements.T, U, V, W, X, Y and Z do not represent the actual symbol of the elements. 1

18 2

13

V

14 X

15

U

16

17 W Y

Z

T

Diagram 2 (a) Write the electron arrangement of U atom. ……………………………………………………………………............................. [1 mark ] (b)

(i) Which of the element exist as a monoatomic gas ? ……....................................................................................................................... [1 mark ] (ii) Explain your answer in (b)(i). ………….…………………………………………………………………………………….

.

……………….............................................................................................................. [2 marks ] (c) V reacts with W to form a compound. (i) Write the formula for the compound formed. ……………………………………………………………………………………… [1 mark ] (ii) Draw the electron arrangement for the compound formed in (c)(i).

[2 marks ]

(d)

(i) Choose an element that is a halogen. …………………………………………………………………………………… [1 mark ] (ii) Which element forms an amphoteric oxide ? …….……………………………………………………………………………… [1 mark ] (iii) Choose the element which form a coloured ion or compound ……………………………………………………………………………………. [1 mark ]

Chemistry Perfect Score/ X A- Plus Module 2012

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3

Table 3 shows the element in Period 3 with their respective proton numbers. Element Proton number

Na

Mg

Al

Si

P

S

Cl

Ar 

11

12

13

14

15

16

17

18

Table 3 (a) (i) Write the electron arrangement of sulphur atom, [1 mark ] (ii) In which group of the Periodic Table is Sulphur, S located ? ..................................................................................................................................... [1 mark ] (b) (i) How does the atomic size change when going across the Period from left to right ? ........................................................................................................................................... [1 mark ] (ii) Explain your answer in 2(b)(i) ...........................................................................................................................................

(c)

............................................................................................................................................ [2 marks ] Argon, Ar is chemically unreactive. Explain why ? .............................................................................................................................................

(d)

............................................................................................................................................ [2 marks ] Which of the element when reacts with oxygen produces an amphoteric oxide ? …………........................................................................................................................... [1 mark ]

(e)

Write the chemical equation when sodium react with water. ......................................................................................................................................... [2 marks ]

4.

Table 4 shows the electron arrangement of atoms of elements J,K,L,M and N.

(a)

Element J K

Electron arrangement of atom 1 2.8.1

L

2.8.6

M

2.8.7

 N

2.8.8

Table 4 State one element in Table 4 which is metal and non-metal? Metal

: .......................................................................................................

 Non- metal

: ........................................................................................................ [2 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

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(b)

(i) State an element that exist as a diatomic gas. Explain your answer. ....……………………………………………………………………………………….. [1 mark ] (ii) Explain your answer in (b)(i)

(c)

…………………………………………………………………………………….... [3 marks] (i) What is the Proton Number for atom M ...................................................................................................................................... [1 mark ] (ii) Which group is atom M located in the Periodic Table ? Explain your answer. .....................................................................................................................................

(d)

.................................................................................................................................... [2 marks ] Arrange atoms K, L and M in increasing atomic size

(e)

....................................................................................................................................... [1 mark ] Write the formula for K ion. ...................................................................................................................................... [1 mark ]

(f)

K and M react to form an ionic compound.State the formula for this compound. ..................................................................................................................................... [1 mark ]

5

(a)

Table 5 shows three substances and their respective chemical formulae. Name of substance

Chemical formula

Chlorine

Cl2

Magnesium

Mg

Magnesium chloride

MgCl2

Table 5 Use information from Table 1 to answer the following questions : (i)

State one substance which exists as an atom. …………………………………………………………………….…………………….[1 mark ]

(ii)

Write the ionic formula for the substance in (a) (i). …………………………………………………………………….……………………. [1 mark ]

(iii)

Which substance has the lowest melting point? …………………………………………………………………….……………………. [1 mark ]

Chemistry Perfect Score/ X A- Plus Module 2012

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(iv)

What is the state of matter of chlorine at room temperature? …………………………………………………………………….……………………. [1 mark ]

(v)

Magnesium chloride can conduct electricity in aqueous solution. Give a reason. …………………………………………………………………….……………………. [1 mark ]

(b)

Graph 1 shows the temperature against time when molten of acetamide, C 2H5 NO is cooled. Temperature / 0C

T1 A

T2

B

C

D

T3

Time / s

Graph 1 (i)

State the type of compound of acetamide. ..........………………………………………………………………………………… [1mark ]

(ii)

State the melting point of acetamide. ……………….………………………………………………………………………… [1 mark ]

(iii)

Describe the movement of the particles of acetamide between A and B during cooling. ………………………………………………………………………………………… [1 mark ]

(iv)

Draw the arrangement of particles of acetamide at stage CD.

[1 mark ]

Chemistry Perfect Score/ X A- Plus Module 2012

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6

(a)

In a close container, contains 3.0 dm 3 of carbon dioxide gas at room temperature. (i)

How many molecules are there in 3.0 dm 3 of carbon dioxide gas, CO 2 ? [Avogadro’s number = 6.02 x 10 23 mol-1] [1 mole of gas occupies 24 dm 3 at room temperature] Use: Number of mole = Number of particles 6.02 x 10 23 mol-1

[2 marks] (ii)

(b)

Calculate the mass of carbon dioxide gas in the container  [Relative molecular mass for CO 2 = 44] Use: Number of mole = mass molar mass

[1 mark ] Diagram 6 shows the set-up of apparatus for an experiment to determine the empirical formula of magnesium oxide..

Magnesium ribbon

Heat Diagram 6 Table 1 shows the results of this experiment Description

Mass (g)

Mass of crucible + lid

34.0

Mass of crucible + lid + magnesium ribbon

36.4

Mass of crucible + lid + magnesium oxide

38.0

Table 1 (b)

(i)

What is the meaning of emperical formula ……………………………………………………………………………………. ………………………………………………………………………………….. [1 mark ]

Chemistry Perfect Score/ X A- Plus Module 2012

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(ii)

Base on table 1, calculate the mass of: Magnesium :

Oxygen :

[2 marks]

(iii)

Calculate the ratio of mole of magnesium atoms to oxygen atoms. [Relative atomic mass: O=16, Mg =24]

[1 mark ] (iv)

Determine the empirical formula of magnesium oxide.

[1 mark ] (v)

Why was the crucible lid opened once in a while during the experiment? …………..……………………………………………………………………….. [1 mark ]

(v)

State why the empirical formula of copper oxide cannot be determine by using the same technique.

…………..……………………………………………………………………….. [1 mark ] 7. (a)

What is the meaning of molecular formula? ……………………………………………………………………………………... …………………………………………………………………………………….. [1 mark ]

(b) Diagram 7.1 shows an incomplete equation which is one of the steps involved in determining the empirical formula. Complete this equation.

Mass Relative atomic mass

= ……………………………

Diagram 7.1

Chemistry Perfect Score/ X A- Plus Module 2012

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(c) Diagram 7.2 shows the apparatus set-up for two methods used to determine the empirical f ormula of two compounds. Method 1 Method II

Diagram 7.2 (i) Which method is suitable to be used to determine the empirical formula of magnesium oxide? ………………………………………………………………………………….…………… [1 mark ] (ii) Why did you choose the method in 2(c)(i)? ……………………………………………………………………………….…………… [1 mark ] (iii) When carrying out an experiment using Method I, why does the crucible lid need to be opened once a while? ……………………………………………………………………………………………… ……………………………………………………………………………………………… [1 mark ] (d) Diagram 7.3 shows the results for an experiment to determine the empirical formula of lead oxide. Mass of combustion tube + porcelain dish

= 54.00 g

Mass of combustion tube + porcelain dish + lead oxide

= 107.52 g

Mass of combustion tube + porcelain dish + lead

= 103.68 g

Diagram 7.3 Based on Diagram 2.3, determine the values of the following [Relative atomic mass of O =16 , Pb = 207] (i) Mass of lead = ………………………… g [1 mark ] (ii) Number of moles of lead. = ……………………………mol [1 mark ] (iii) Mass of oxygen = …………………………..g [1 mark ] (iv) Number of moles of oxygen. = ……………………………mol [1 mark ] (v) Empirical formula of oxide of lead. = …………………………… [1 mark ] Chemistry Perfect Score/ X A- Plus Module 2012

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8.

Diagram 8 shows the apparatus set-up to determine the empirical formula of copper oxide.

Diagram 8 Table 8 shows the result of this experiment. Description Combustion tube + porcelain dish Combustion tube + porcelain dish + copper oxide Combustion tube + porcelain dish + copper

Mass(g) 42.25 52.25 50.25

Table 8 (a) (i) What is the meaning of empirical formula? ……………………………………………………………………………………… ……………………………………………………………………………………… [1 mark ] (ii) State the function of the anhydrous calcium chloride. ……………………………………………………………………………………….. [1 mark ] (b) (i) Based on Table 8, determine the mass of: Copper: =………………………………..g Oxygen: = ………………………………..g [2 marks]

(ii) Calculate the ratio of moles of copper atoms to oxygen atoms. [Relative atomic mass: O = 16 ; Cu = 64]

[1 mark ] Chemistry Perfect Score/ X A- Plus Module 2012

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(iii) Determine the empirical formula of copper oxide. ……………………………………………………………………………………… [1 mark ] (c) (i) Why is hydrogen gas passed through the combustion tube after heating has stopped? ………………………………………………………………………………………. ………………………………………………………………………………………. [1 mark ] (ii) State how to determine that the reaction between copper oxide with hydrogen has completed. ……………………………………………………………………………………… ……………………………………………………………………………………… [1 mark ] (d) (i) State why the empirical formula of magnesium oxide cannot be determined by using the same technique. …………………………………………………………………………………… …………………………………………………………………………………… [1 mark ] (ii) State the name of another metal oxide whose empirical formula can be determine using the same technique. ………………………………………………………………………………….. [1 mark ]

9

(a)

SECTION B Diagram 9.1 shows the atomic structure of two carbon isotopes.

 Nucleus 6 neutrons

 Nucleus 8 neutrons

Diagram 9.1 (a) Compare the two isotopes above in terms of number of proton, number of electron, nucleon number,physical properties and chemical properties. [6 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

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(b) Diagram 9.2 shows the set up of apparatus used in experiment to determine the melting  points of X. Q

X

P

Heat (i)

Diagram 9.2 Suggest one example of substance X. [1 mark ]

(ii)

State the name of P. Explain why P is used? [2 marks]

(iii) Graph 9 shows the heating curve of X. Temperature / 0 C 100

80

30 0

t1

t2

t3

Time/ minutes

Graph 9 Describe Graph 9 in terms of state of matter, particles arrangement, kinetic energy of   particles and attraction forces between particles. [10 marks] (iv) After t3 minutes, X is cooled at room temperature. Sketch a graph of temperature against time for cooling process. . [2 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

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10

(a)

4

Helium, 2  He exists as a monoatomic gas whereas chlorine,

35 17 Cl 

exists as a diatomic gas.

Explain why. [6 marks] (b)

Table 10.1 shows the proton number of magnesium, chlorine and carbon. Element

Magnesium

Chlorine

Carbon

12

17

6

Proton number

Table 10.1 (i)

Carbon reacts with chlorine to form a compound. What type of the compound formed? Draw the electron arrangement to show the chemical bond in the compound. [3 marks]

(ii)

Explain how ionic bond is formed between magnesium and chlorine atoms. [7 marks]

(c)

Diagram 10 shows the set-up of apparatus to investigate the electrical conductivity of  naphthalene and sodium chloride solution. Bulb Carbon electrode Compound Diagram 10 Table 10.2 shows the result of the experiments. Compound

Observation

 Naphthalene

Bulb does not light up

Sodium chloride solution

Bulb lights up

Table 10.2 Explain the electrical conductivity of the two compounds. [4 marks]

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11. (a) The following are the formulae of two compounds. Al2O3

PbO2

(i) Based on the two formulae, write the formula for ion aluminium and ion lead [2 marks] (ii) Name both compounds based on the IUPAC nomenclature syst em. [2 marks] (b) The following information is about an organic compound, K. 

Empirical formula is CH 2O.



Relative molecular mass is 60.



Reacts with calcium carbonate to produce a type of gas that turns lime water chalky.

Based on the information given: (i) Determine the molecular formula of K. [Relative atomic mass : H = 1, C = 12, O = 16] [3 marks] (ii) Write a balanced chemical equation for the reaction of compound K with calcium carbonate. [2 marks]

(c) Diagram 11 shows the apparatus set up for experiment of decomposition of copper(II) carbonate. In this experiment copper(II) oxide and carbon dioxide gas are f ormed.

Copper(II) carbonate powder 

Heat Lime water  Diagram 11 Based on Diagram 11 (i) State two observations. [2 marks] (ii) Write a balanced chemical equation for the r eaction [2 marks] (iii) ) State two informations from the chemical equation in (c)(ii). [2 marks]

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(v)

Calculate the mass of the copper(II) oxide formed from the decomposition of 12.4 g of  copper(II) carbonate. [ Relative atomic mass of C = 12; O = 16; Cu = 64 ] [3 marks]

(vi)

12.

In other experiment 4.0 g copper(II) oxide is reacted with hydrogen gas to produce copper and water. If the mass of copper in copper(II) oxide is 3.2 g, calculate the mass of oxygen and the simplest mole ratio for the copper atoms to oxygen atoms [ Relative atomic mass of O = 16; Cu = 64 ] [2 marks] Table 12 shows the positive and negative ions in three salts solution.  Name of salt Iron(III) chloride Potassium sulphate Lead(II) nitrate

Positive ion Fe3+ K + Pb 2+

Negative ion ClSO42NO3-

Table 12 Use the information in Table 12 to answer the following questions. (a) (i) What are another name for a positively charged ion and negatively charged ion? [2 marks] (ii) Name the ions in iron(III) chloride. [2 marks] (iii) Write the formula for potassium sulphate. [1 mark ] (b) When 10 cm 3 of 0.5 mol dm -3 potassium sulphate solution is added to excess lead(II) nitrate solution, a white precipitate is formed. (i) Name the white precipitate and write the chemical equation for the reaction. [3 marks] (ii) Describe the chemical equation in (b)(i). [1 mark ] (iii) Calculate the mass of precipitate formed. [Relative atomic mass of O = 16; S = 32; Pb = 207] [4 marks] (c) The information below is regarding an organic compound Z. 

Relative molecular mass is 46



Carbon : 52.2%



Hydrogen : 13.0%



Oxygen : 34.8%



Relative atomic mass of H = 1; C = 12 and O = 16

Based on the information of the organic compound Z: (i) Determine the molecular formula for compound Z and

[6 marks]

(ii) Draw its structural formula. [1 mark ]

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SECTION C 13

(a)

An experiment is carried out using Group 1 elements; X, Y and Z react with oxygen gas.The set-up of apparatus and observations of the reaction are shown in Table 13. Set

Set-up of apparatus

Observation

Burns slowly and white fumes formed

I X

Burns vigorously and white fumes formed

II Y

Burns rapidly and white fumes formed

III Z

(b) (c)

Table 13 (i) Based on the observation in Table 13, compare the reactivity of element X and Y. Explain your answer. [5 marks] (ii) Suggest the name of element Z. Using the symbol of element suggested, write the chemical equation for the reaction in set III. [3 marks] State how elements of Group 1 are stored in laboratory and give a reason. [2 marks] Group 1 elements react with water to produce alkaline solution. Using an example of Group 1 element, describe an experiment to prove above statement. Your description should include the following :    

List of material and apparatus Procedures of the experiment Observation Chemical equation [10 marks]

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14

Table 14 shows the melting point, boiling point and electrical conductivity of compound PQ 2 and compound XY. Compound

Melting point and Boiling point

Electrical conductivity Solid

Molten

P

Low

No

No

Q

High

No

Yes

Table 14 Suggest one possible compound for  P. State the type of compound for  P. Explain why P has low melting and boiling points.

(a)

[4 marks] (b)

Chemical formula of compound P is XY. Suggest one possible electron arrangement of atom X and atom Y. State the type of chemical bond and explain how the bond is formed between atom X and atom Y. [7 marks] Plan one laboratory experiment to investigate the electrical conductivity of compound Q. Your answer should include the following : A list of material and apparatus   Procedure of the experiment Observation of the experiment   A labeled diagram showing the apparatus set-up [9 marks]

(c)

15 (a) Metal P has the following characteristics:  

Grey in colour  Can react with steam Reactive metal

Based on the information above, state the method used to determine the empirical formula of oxide of  metal P. Give a reason for your answer . [2 marks] (b) Diagram 15 shows the set up of apparatus for an experiment to determine the empirical formula of the oxide of metal Y. Combustion tube

Dry hydrogen

Oxide of metal Y Diagram 15 The results are obtained as follows: Mass of combustion tube + Porcelain dish = 54.30 g Mass of combustion tube + Porcelain dish + Oxide of Metal Y = 56.69 g Mass of combustion tube + Porcelain dish + Metal Y = 56.37 g Table 15

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(i) Based on the above information, determine the empirical formula of oxide of metal Y Given that the relative atomic mass of O = 16, Y = 207 [4 marks]

(ii) Describe the steps that should be taken to ensure that all the air in t he combustion tube has been expelled . [3 marks] (b) Describe an experiment on how to determine the empirical formula of magnesium oxide. In your  description, state the precautions should be taken during the experiment and show how the empirical formula of magnesium oxide is obtained. [Relative atomic mass: O = 16; Mg = 24] [11 marks]

16. (a) The following is the chemical formula of a compound. SO3  Name the compound and describe the composition of this compound. [3 marks] (b) Excess calcium carbonate chips is added to 30 cm 3 of 0.5 mol dm -3 acid HX. The chemical equation below shows t he reaction between calcium carbonate and acid HX. CaCO3

+

nHX

CaX2

+

CO2

+

H2O

Given that the relative atomic mass of C = 12, O = 16 , Ca = 40 and the molar  volume of any gas is 24 dm 3 mol-1 at room temperature and pressure. (i) Suggest acid HX and name salt CaX 2 Determine the value of n [3 marks] (ii) Calculate the maximum volume of carbon dioxide gas produced. [4 marks] (c) You are provided with a sample of M oxide powder. The colour of the M oxide powder is green while the colour of metal M is grey. When it is heated with hydrogen, the M oxide is reduced to M metal. Based on the information given, describe an experiment to determine the empirical formula of the M oxide. In your description, include the precautions that should be taken and show how the empirical formula of M oxide is obtained. [Relative atomic mass of O = 16 and M = 56] [10 marks]

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CHEMISTRY MODULE

SET



1. Electrochemistry 2. Oxidation and Reduction

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SECTION A 1

Diagram 1 shows the set-up of apparatus of a voltaic cell.

V

Zinc plate

Copper plate Copper(II) nitrate solution

Diagram 1 Based on Diagram 1 , answer the following questions. (a)

What is the energy change that occurs in the voltaic cell? .................................................................................................................................. [1 mark ]

(b)

Write the formula of all ions in copper(II) sulphate solution. .................................................................................................................................. [1 mark ] (i)

State the name of the negative terminal of the voltaic cell.

……............................................................................................................................... [1 mark ] (ii)

Give a reason for your answer in (c)(i). ..................................................................................................................... [1 mark ]

(d)

(i)

State one observation at copper plate. ..................................................................................................................... [1 mark ]

(ii)

Write the half equation for the reaction occur at the copper plate. ..................................................................................................................... [1 mark ]

(e)

What is the colour change of the copper(II) sulphate solution? Give a reason. .................................................................................................................................. .................................................................................................................................. [2 marks]

(f)

Another experiment is carried out by replacing the zinc plate with P , Q and R metals. Table 1 shows the results. .Pair of metal

Voltage/V

Negative terminal

P/Cu

2.7

P

Q/Cu

2.0

Q

R/Cu

0.5

R  Table 1

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(i) Arrange P, Q, R and Cu metal in accending order of electropositivity. .................................................................................................................................. [1 mark ] (ii) Predict the voltage for pair of Q/R. .................................................................................................................................. 2.

[1 mark ] Diagram 2 shows the set-up of apparatus to investigate the reaction occurred in test tubes X and Y. Test tube X

Test tube Y Agar solution + Potassium hexacyanoferrate(III) solution + Phenolphthalein Iron(III) sulphate solution

Iron nail coiled with zinc

Zinc Diagram 2

Heat (a)

Based on test tube X, (i) Name the reaction occurred.

(ii)

………………………………………………………………………………… [1 mark ] Write the ionic equation for the reaction.

(iii)

………………………………………………………………………………… [2 marks] Describe a chemical test to verify the product formed. ........................................................................................................ .......................................................................................................... [2 marks]

(b)

Based on test tube Y, (i)

State the observation involved. ................................................................................................................ [1 mark ]

(ii)

Experiment is repeated by using copper to replace zinc. State the observation involved. ..................................................................................................................

[1 mark ] (c) Compare the answer in (b) (i) and (b) (ii) and explain why there is a diffe rence in the observation. ............................................................................................................................................. ............................................................................................................................................. [2 marks] (d) When iron is exposed to water and oxygen, it rusts easily. State one method to prevent the rusting of  iron. .......................................................................................................................................... [1 mark ] Chemistry Perfect Score/ X A- Plus Module 2012

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SECTION B 3

Diagram 3.1 shows the set-up of apparatus to investigate the electrolysis of magnesium chloride 1.0 mol dm -3 solution.

Carbon electrodes

Magnesium chloride 1.0 mol dm -3

A

(a)

(i)

(ii)

Diagram 3.1 Based on Diagram 3.1; State the name of the products at the cathode and the anode. Explain the reaction at cathode and anode. Include the following in your explanation:  List the ions attracted to cathode and anode.  State the ions selectively discharged at cathode and anode. The reason why the ions are selectively discharged.   Half equation for the reaction at cathode and anode. [10 marks] -3 Predict the product at anode and cathode if magnesium chloride 1.0 mol dm solution is replaced by magnesium chloride 0.0001 mol dm -3 solution. [2 marks]

(b)

Diagram 3.2 shows the set up of apparatus when cell X is combined with cell Y.

V

Magnesium  plate

Copper plate

Copper plate

Copper(II) sulphate solution Cell X

Diagram 3.2

Cell Y

Compare and contrast cell X and cell Y in terms of following:      

Types of cells Energy changes  Name of electrodes Ions in the electrolyte Half equations Observations . [8 marks]

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4

(a) The following are the formulae of two compounds.

 Na2O (i)

PbO2

Based on the two formulae , state the oxidation number for sodium and lead. [ 2 marks]

(ii)

State the name of the compounds based on the IUPAC nomenclature. [ 2 marks]

(b) Diagram 4 shows the observation of two experiment to study the effect of metal P and metal Q on the rusting of iron. Experiment Experiment 1

Observation

Large amount of dark blue precipitate

Experiment 2

 No dark blue precipitate. Solution turns pink.

(i) (ii)

(c)

Diagram 4 Suggest metal P and metal Q. Explain the observations and write the chemical equation for the reaction in the experiment 1 and experiment 2. [ 10 marks]

The equation shows a redox reaction. M is a metal. X(s)

+

CuSO4 (aq)

XSO4 (aq) +

Cu(s)

Suggest metal X and explain the redox reaction in terms of the transfer of electrons . [6 marks]

5

SECTION C Diagram 5 shows the set-up of apparatus for electrolysis of 1.0 mol dm -3 sodium sulphate solution.

1.0 moldm - sodium sulphate solution Carbon electrode X

Carbon electrode Y

Diagram 5 (a)

State the name of gas produced at electrode X and electrode Y.

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(b)

Explain the reaction at electrode X and electrode Y. Include the following inyour explanation. List of ion attracted to each electrodes, X and Y.   State the name of the ions selectively discharged at each electrode.  The reason why the ion are selectively discharged. [5 marks] When sodium sulphate solution is replaced by a solution of substance Z with same concentration, the equal gas produced at electrode X and electrode Y . Suggest the substance Z. Write the half equation for the reaction at electrode X. [3 marks] Zinc is placed above metal A in the electrochemical series. Zinc and metal A can be used to build a chemical cell, using suitable apparatus and the following chemicals ;

(c)

(d)

Zinc Zinc nitrate solution Metal A A nitrate solution By naming metal A and A nitrate solution, describe how you build the chemical cell. Include a labelled diagram in your answer. On your diagram, mark the direction of electron flow, the positive terminal and the negative terminal. [ 10 marks] 6

(a)

The following are the equations of two reactions: Reaction I

:

NaOH

Reaction II

:

Mg

+

+

HCl

NaCl

Zn(NO3)2

+

Mg(NO3)2

H2O +

Zn

Determine which reaction is a redox reaction. Explain your answer in terms of oxidation number. [4 marks] (b) Table 6 shows the observations of two experiments to determine the position of carbon in the reactivity series of metal. Experiment

Reactants

Observation

I

Carbon + oxide of metal P

A flame spreads to the whole mixture. A brown residue is formed.

II

Carbon + oxide of metal Q

No change

III

Carbon + oxide of metal R 

A glow spreads to the whole mixture. A grey residue is formed.

Table 6 Based on observations in Table 6, arrange the reactivity of metals P, Q, and R in descending order. Explain your answer. [6 marks] (c)

Iron(II) ions can be converted to iron(III) ions and iron(III) ions can be converted back to iron(II) ions.

By using a named metal as a reducing agent and a named halogen as an oxidising agent, describe  briefly how you would carry out these two conversion. Describe a test to show that each conversion has taken place. [ 10 marks]

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CHEMISTRY MODULE

SET



1. Acids and Bases 2. Salts 3. Rate of reaction 4. Thermochemistry

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SECTION A

1.

Diagram 1 shows four test tubes labeled A,B,C and D which are used to study the relationship  between pH value of acid and alkali with the molarity.  pH paper 

A 5 cm HCl 0.1 mol dm-3 3

B 5 cm HCl 0.01 mol dm -3 3

C 5 cm  NaOH 0.1 mol dm -3 3

D 5 cm  NaOH 0.01 moldm-3 3

Diagram 1 (a)

Determine which solution has (i) highest pH value. `

…………….……………………………………………………………………………........ [1 mark ] (ii) lowest pH value. Give a reason for your answer. ………………………………………………………………………………………............. [2 marks] (b)

If the hydrochloric acid in test tube B is replaced with 5 cm 3 of 0 .01 mol dm -3ethanoic acid,  predict the pH value of the solution. Explain your answer 

…………………………………………………………………………………………………...……….. ………………………………………………………………………………………………… ……………………………………………………………………………………………. [3 marks] (c)

Excess of magnesium powder is added to 5 cm 3 of 0.1moldm -3 hydrochloric acid in test tube A (i) State the name of the products formed.

. ……...……………………………………………………………………………………….. [1 mark ] (ii) Write the chemical equation for the reaction in test tube A ……………………………………………………………………………………………… [1 mark ] (iii) Calculate volume of hydrogen gas released at room conditions in test tube A [1 mol of gas occupies 24 dm3 at room conditions]

[3 marks]

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(d)

If the solution in test tube C is added to lead(II) nitrate solution. State the observation from the reaction. …….………………………………………………………………………………………… [1 mark ]

2. (a)

Diagram 2.1 shows the pH value of glacial ethanoic acid in solvent P and solvent Q respectively.

7.0

4.8

Glacial ethanoic acid + solvent P

Glacial ethanoic acid + solvent Q

Diagram 2.1 (i)

Suggest solvent P and solvent Q. Solvent P: ……………………………………………………….………...……………… Solvent Q: ………………………………………………………………………………. [2 marks]

(ii)

(iii)

If magnesium ribbon is added into beaker containing glacial ethanoic acid and solvent P, what can be observed? ……………………………………….………………………………………………… [1 mark ] Explain why ethanoic acid in solvent P and solvent Q has different the pH value. ….……………………………………………………………………………………… ….……………………………………………………………………………………… ….……………………………………………………………………………………… ...……………………………………………………………………………………… [3 marks]

(b)

Diagram 2.2 shows the concentration of hydrochloric acid in volumetric flask when a certain volume of hydrochloric from the beaker is transferred to the volumetric flask and added with water 

Add water 

100 cm of 0.5 moldm- hydrochloric acid

3

Diagram 2.2

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-3

250 cm of 0.04 moldm hydrochloric acid

36

(i)

What happen to the pH value of the hydrochloric acid when water is added to the acid? Give a reason for your answer. ….…………………………………………………………………………………………… .……………………………………………………………………………………………… [2 marks]

(ii)

Calculate the volume of hydrochloric acid that is needed to prepare 250cm 3 of 0.04 mol dm -3 hydrochloric acid.

[2 marks] 3. A student carried out an experiment to investigate the p roperties of three solutions. Diagram 3 shows the results of the experiments. Test tube Set-up of  apparatus

Observation

(a)

P

Q

R 

Red litmus Paper 

Red litmus Paper 

Magnesium

Ammonia gas dissolved in water 

Ammonia gas dissolved in  propanone

Hydrogen chloride gas dissolved in water 

The red litmus  paper turned blue.

 No change

Diagram 3 What is meant by strong alkali? ....................................................................................................................................... [1 mark ]

(b)

What is the property of the solution in test tube P? ....................................................................................................................................... [1 mark ]

(c)

What are the types of particles that exist in the test tubes P and Q? Particles in the test tube P: .......................................................................................... Particles in the test tube Q: .........................................................................................

(d)

[2 marks] Is there any changes of colour of the litmus paper in test tube Q? Give a reason to your answer. ...................................................................................................................................... ...................................................................................................................................... [2 marks]

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(e)

(i)

What can be observed in test tube R? ...................................................................................................................................... [1 mark ]

(ii)

Write a chemical equation for the reaction in test tube R. ....................................................................................................................................... [2 marks]

(iii)

2.4 g of magnesium is reacted completely with the solution in test tube R. Calculate the volume of the hydrogen gas produced at room condition [Relative atomic mass: Mg,24; 1 mol of gas occupies 24 dm 3 at room conditions]

[2 marks]

4

Diagram 4 shows the apparatus set-upfor the neutralisation reaction between sulphuric acid and  potassium hydroxide solution for preparation of salt X.

15 cm of 0.1mol dmsulphuric acid

25.0 cm3  potassium hydroxide solution + phenolphthalein indicator 

Diagram 4 (a) (i)

State the colour change of the solution in the conical flask at the end point.

(ii)

………………………………………………………………………………….………………… [1 mark] Write a chemical equation for the above reaction.

(iii)

……………………………………………………………………………………………………. [2 marks] Calculate the concentration of potassium hydroxide used.

[2 marks] (b) (i)

State the name of salt X. ……………………………………………………………………………………………..

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[1 marks] (ii)

Calculate the maximum mass of salt X formed. [Molar mass of salt X = 174 g mol -1]

[3 marks] The experiment is repeated with 0.1 mol dm nitric acid to replace sulphuric acid. Predict the volume of nitric acid needed to neutralize completely potassium hydroxide -3

(c) (i)

(iii)

……………………………………………………………………………………………….. [1 mark] Explain your answer in (c) (i). ...................................................................................................................................................... ...................................................................................................................................................... [2marks]

5. Diagram 5 shows a series reaction of copper compound. Copper(II) nitrate

Sodium carbonate

Copper(II) carbonate

Heat

Copper(II) oxide

+

Gas X

Acid Y Copper(II) sulphate Diagram 5 (a)

Copper(II) nitrate solution reacts with sodium carbonate solution to form copper(II) carbonate  precipitate. (i) What is the colour of copper(II) carbonate?

(ii)

………………………………………………………………………………………............. [1 mark ] State the name of the reaction. ......................................................................................................................................................... [1 mark ] Heating of copper(II) carbonate produces copper(II) oxide and gas X.

(b) (i)

State the name of gas X.

(ii)

……………………………………………………………………………………………….. [1 mark ] Write the chemical equation of the reaction.

.............................................………………………………………………………...................... [2 mark ]

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(iv)

Draw a labeled diagram for the heating of copper(II) carbonate to produce copper(II) oxide and gas X. In your diagram show how gas X is tested.

[2 marks] (c) Copper(II) carbonate reacts with acid Y to produce copper(II) sulphate. The chemical equation is shown below. CuCO 3 + Acid Y → CuSO4 + CO2 + H2O (i) What is acid Y?

(ii)

………………………………………………………………………………………………… [1 mark ] 12.4 g copper(II) carbonate reacts completely with excess acid Y. Calculate the mass of copper(II) sulphate formed. [Relative atomic mass: C = 12, O=16 , S = 32, Cu = 64]

[3 marks] 6. Three experiments were conducted to investigate factors affecting the rate of reaction. The results a re shown in the Table 6 Temperature / 0C

Time taken for all the magnesium to dissolve/s

I

0.4g magnesium ribbon and 50 cm 3 1 moldm-3 hydrochloric acid

30

100

II

0.4g magnesium powder and 50 cm 3 1 moldm-3 hydrochloric acid

30

60

III

0.4g magnesium ribbon and 50 cm 3 1 moldm-3 hydrochloric acid and copper(II) sulphate solution

30

45

Experiment

Reactants

Table 6 (a)

Write a chemical equation to show the reaction between magnesium and hydrochloric acid.

(b)

……………………………………………………………………………………………… [2 marks] Calculate the number of mole of  (i)

Magnesium [Relative atomic mass of Mg = 24]

[1 mark] (ii)

Hydrochloric acid

[1 mark]

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(c)

If hydrochloric acid used is excess, calculate the maximum volume of hydrogen gas produce at room temperature and pressure. [1 mole of gas occupies the volume of 24 dm 3 at room temperature and pressure]

[2 marks] (d)

Calculate the average rate of reaction for  (i) Experiment I

[1 mark] (ii)

Experiment II.

[1 mark] (iii)

What is the purpose of using copper(II) sulphate?

…….……………………………………………………………………………………… [1 mark] (f)

The factor that affects the rate of reaction in this experiment is total surface area and the use of  catalyst. State two other factors that affect the rate reaction in this experiment. ………………………………………………………………………………………………

……..……………………………………………………………………………………… [2 marks] 7. Diagram 7 shows two experiments to investigate one of the factors that affect the rate of reaction between zinc and hydrochloric acid Hydrogen gas

Experiment I

50 cm3 1 mol dm-3HCl Excess zinc granules

Hydrogen gas

50 cm 1 mol dm- HCl + copper(II) sulphate solution

Experiment II

Excess zinc granules

Diagram 7 (a) (i) Based on Diagram 7, state the factor that affect the rate of reaction in this experiment. …………………………………………………………………………………………………. [1 mark]

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(ii) Besides measuring the change of volume of gas released at certain time interval, suggest another  measurable change to determine the rate of reaction? ………………………………………………………………………………………………….. [1 mark] (b) In Experiment II, 2.0 cm 3 0.5 moldm-3copper(II) sulphate solution is added. The maximum volume of  hydrogen gas released in Experiment I is V cm 3. (i) Compare the volume of gas released in Experiment I and Experiment II. Give a reason for your answer. ………………………………………………………………………………………………….. …………………………………………………………………………………………………. [2 marks] (ii) The graph of volume of hydrogen gas released against time in Experiment I is shown below. Volume of gas released/ cm3

Key : Experiment I : Experiment II :

…

Time / s

Sketch the curve for Experiment II on the same axes in the graph above. [2 marks] (iii) With reference to collision theory, explain how copper(II) sulphate solution affect the rate o f  reaction in this experiment. [3 marks] (c) Table 7.1 shows three experiments done by a student. Experiment A B C

Reactants Excess calcium carbonate chips + 25 cm 3 1.0 mol dm -3 hydrochloric acid Excess calcium carbonate chips + 25 cm 0.5 mol dm hydrochloric acid Excess calcium carbonate chips + 100 cm 0.5 mol dm hydrochloric acid Table 7.1

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The graph of volume of carbon dioxide released against time is sketched as shown in graph 7 Based on the above table and graph, determine which curve represents the results for experiment B and C. Write your answers in the boxes provided. Volume of  carbon dioxide /cm3

Experiment

Graph 7

Time/s [1 mark]

8.

An experiment is conducted to study the heat of displacement for reaction between copper(II) sulphate and excess magnesium powder. 50.0 cm3 of 0.5 mol dm -3 copper(II) sulphate solution is poured into a  polystyrene cup and the initial temperature is recorded. The excess magnesium powder is added to the same polystyrene cup. The mixture is stirred slowly and the highest temperature is recorded. Initial temperature of copper(II) sulphate solution = 28.5 oC Highest temperature of mixture = 33.5 oC [Relative atomic mass : Cu=64; S=32; O=16; Zn= 65; (a)

What is the meaning of heat of displacement in this experiment? ............................................................................................................................ ............................................................................................................................

(b)

Why does zinc in the form of powder is used in this experiment?

………………………………………………………………………………………… (c)

[1 mark ]

[1 mark ]

Write the ionic equation for the reaction in this experiment. ............................................................................................................................ [2 marks]

(d)

(i)

Based on the experiment, calculate the heat energy released. [1 mark ]

(ii) number of mole of copper(II) sulphate that has reacted [1 mark ] (iii) heat of displacement in this reaction

[2 marks] (e)

Draw an energy level diagram for the reaction.

[3 marks]

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(f)

Why polystyrene cup is used in this experiment?

………………………………………………………………………………………………………… [1 mark ] 9.

Diagram 9 shows the apparatus set-up to determine heat of displacement of copper by using zinc  powder. The result of the experiment is recorded in the Table 9.

5 g of zinc powder 

Plastic cup 50 cm3 of 0.2 mol dm -3 copper(II) sulphate solution

Diagram 9 Initial temperature of copper(II) sulphate solution ( oC) o

Highest temperature of the mixture ( C)

30.0 38.0

Table 9 (a)

What is the meaning of heat of displacement? ……………………………………………………………………………………… ……………………………………………………………………………………… [1 mark ]

(b)

Why plastic cup is used in this experiment. ………………………………………………………………………………………

(c)

[1 mark ]

State the type of reaction that occurs based on the temperature change. ……………………………………………………………………………………… [1 mark ]

(d)

Calculate : (i) the heat change for the reaction [Specific heat capacity of solution = 4.2 J g-1 oC-1; Density of solution = 1 g cm -3]

[1 mark ] (ii)

the heat of displacement for the reaction.

[2 marks] (e)

Draw energy level diagram for the reaction.

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(f)

Experiment is repeated by using 100 cm 3 of 0.2 mol dm -3 of copper(II) sulphate solution. (i)

Predict the temperature change in the experiment. . ……………………………………………………………………………………... [1 mark ]

(ii)

Explain your answer in (e) (i). ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... [2 marks]

10.

The equation for combustion of propanol in excess oxygen is given below. C3H7OH

(a)

+ 9 O2 2

3CO2 + 4H2O , ∆H = -2015 kJ mol -1

What is meant by heat of combustion in this reaction? ..........................................……………………………………………………………………… [1 mark]

(b)

State two information that can be obtained from the equation ...........................................…………………………………………………………………… ………………………………………………………………………………………………

(c)

[2 mark] Heat given out from the complete combustion of 1.2 g propanol is used to heat 200 cm of water. Calculate: (i) The heat energy given out in the reaction. [Molar mass of propanol, C 3H7OH = 60 gmol -1] 3

[2 marks] (ii)

The temperature change in the reaction. [Spesific heat capacity of water = 4.2 Jg -1 oC-1 ; Density of water = 1 gcm-3 ] [2 marks]

(d)

Draw the energy level diagram for this reaction.

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(e)

The value of the heat of combustion of propanol obtained from the experiment experiment is less than the theoretical value. Suggest one precaution step that should be taken in order to get a more accurate result.

.......................................................... ............................................................................................ .......................................................................................... ................................................................ ........ [1 mark] (f)

Table 10 show s the molecular formula and and the heat of combustion for methanol and ethanol. Molecular formula

Heat of combustion/kJmol -1

Methanol

CH3OH

-728

Ethanol

C2H5OH

-1376

Alcohol

Table 10 Based on the information in Table 10, explain why there is a difference in the value of heat of  combustion between methanol and ethanol. .......................................................... ............................................................................................ .............................................................. .................................. .................. ............ .......................................................... ............................................................................................ ................................................................................ .............................................. .......................................................... ............................................................................................ .............................................................. .................................. .................. ............ .......................................................... ................................................................................................................ ................................................................................ .......................... [3 marks]

11.

SECTION B (a) A student student has carried out an experiment to construct construct an ionic equation equation for the formation of lead(II) iodide. Seven test tubes of the same size were were labeled 1 to 7. A fixed volume volume of 5.0 cm 3 of 1.0 mol dm-3 potassium iodide solution was poured poured in each test tube. The volume of 1.0 mol dm -3lead(II) nitrate solution that added are shown shown in Table 11. The height of precipitate precipitate formed in each test tube was measured. The results are shown in Table 11.

Test tube

1

2

3

4

5

6

7

Volume of 1.0 moldm lead(II) 3 nitrate solution / cm

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Height of precipitate /cm

1.1

2.2

3.4

4.4

5.5

5.5

5.5

-3

Table 11

(i)

Based on Table 11, plot a graph of the height of precipitate against volume of lead(II) nitrate solution. [3 marks] marks]

(ii)

Determine the number of moles of lead(II) ions and iodide ions that are required for the the formation of lead(II) lead(II) iodide. iodide. Your answer should consist of the following:    

the volume of lead(II) nitrate solution that had reacted completely with 5.0 cm 3 of 1.0 mol dm-3 potassium iodide calcúlate the number of moles of lead(II) ions and iodide ions calculate the number of moles of iodide iodide ions that has reacted with 1 mol of lead(II) ions. write the ionic equation for the formation of lead(II) iodide. [7 marks] marks]

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(b)

Diagram 11 shows the flow chart of reaction reaction of salt J. X oxide which is brown brown when hot and yellow when cold is formed when salt salt J is heated strongly. Salt J dissolves in water to form colourless solution. The solution formed is tested with potassium iodide, KI solution.

Salt J

∆

H2O

X Oxide

+

Brown gas Y

Colourless gas Z

+

Potassium iodide solution

Salt J solution

Yellow precipitate L

Diagram 11 Based on the information in Diagram 11: (i) Identify salt J, X oxide, brown gas Y, colourless colourless gas Z and yellow precipitate L. (ii)

12.

[5 marks] marks] State the name of the anion present in salt J. T hen describe one chemical test to determine the  presence of anion in salt J. [5 marks] marks]

Diagram 12.1 shows a series of reaction for salt S which is a green colour compound. Salt S is heated strongly to produce black residue of compound T and gas U. Compound T reacts with sulphuric acid to form blue solution of compound W.

Salt S

Heat

+

Compound T

Pass through lime water 

+ H2SO4

Compound W

Gas U

Lime water turns cloudy

Diagram 12.1 Based on Diargram 12.1: (a) (i)

Suggest one formula of the anion in salt S. [1 mark ]

(ii)

Identify salt S, compound T, gas U and compound W. [4 marks] marks]

(b) Write a chemical equation for the reaction between compound T and sulphuric acid. [2 marks] marks] (c) Compound W is a soluble salt. Describe chemical test to verify the cation and anion in compound W. [5 marks] marks]

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(d) Diagram 12.2 shows the chemical equation for the reaction between blue solution of compound W and  barium nitrate solution.

Compound W(aq)+ Ba(NO3)2(aq)

→ Salt X(s)

+ Salt Y(aq)

Diagram 12.2 Based on Diagram 12.2: (i)

State the name of salt X and salt Y. [2 marks] marks]

(ii)

State one observation and name the type of reaction occurred. [2 marks] marks]

(iii)

Compound W reacts with 50 cm 3 of 0.1 mol dm -3 barium nitrate solution. Write the ionic equation for the reaction and calculate the mass of salt X produced. [Relative molecular mass of salt X: 233] [4 marks] marks]

13 (a) Table 13 shows shows the incomplete incomplete observation for two experiments to construct balanced chemical chemical equation. Experiment

Procedure

A

Copper(II) carbonate is heated and the gas  produced is passed through lime water.. water..

B

Potassium iodide solution is added to lead(II) nitrate solution.

Observation Green solid turns black. The lime water turns milky.

Table 13 (i) Based on the observation, state the name of the products in experiment A and write the chemical equation for the reaction. [3 marks ] (ii) State one observation in experiment B and state the name of the products formed. Write the chemical equation for the reaction. [4 marks ] (b) You are given aluminium aluminium nitrate solution and zinc nitrate solution. Describe chemical tests that can be used to verify the cations and anion in each solutions. [8 marks] marks] (c) Excess of solid copper(II) copper(II) oxide is added added to 25 cm 3 of 1.0 mol dm -3sulphuric acid to form copper(II) sulphate. [Relative atomic mass, Cu=64, S=32, O=16] (i) Write the chemical equation for the reaction (ii) Calculate the mass of copper (II) (II) sulphate produced [5 marks] marks]

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14 (a)

(i)

Rate of a given reaction is important in industries and in our everyday lives. State the four factors that affect the rate of reaction.

[4 marks]

(ii) What are the conditions required for the production of ammonia in Haber Process?

[3 marks]

(b) A student carried out two experiments to investigate the effect of concentration on the rate of reaction. Diagram 3.1 shows the set-up of apparatus of the experiments. Experiment

Set-up of apparatus

Excess hydrochloric acid 0.2mol dm -3 I

Water   Air 

0.2 g calcium carbonate  powder 

Excess hydrochloric acid -3 0.5mol dm

II

Water   Air 

0.2 g calcium carbonate  powder  Diagram 14.1

Table 14.2 shows the result of the experiments. Time /s

0

30

60

90

120

150

180

210

Volume of gas of Experiment I /cm3

0.00

5.00

10.00

14.20

18.00

21.30

24.00

26.00

Volume of gas of Experiment II /cm3

0.00

10.00

17.00

23.00

25.00

26.00

26.00

26.00

Table 14.2 (i)

(ii) (iii)

Plot the graph of the volume of carbon dioxide gas against time for Experiment I and II on the same axes on the graph paper provided . [4 marks] Calculate the average rate of reaction for Experiment I and II. [4 marks] Compare the rate of reaction between Experiment I and Experiment II. Explain the differences in the rate of reaction with reference to the collision theory. [5 marks]

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Question 14 (b) (i)

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15. (a) A fixed mass of magnesium is added to 50 cm 3 0.5 mol dm -3 of excess sulphuric acid . State 3 ways to shorten the time for the magnesium to dissolve completely. [3 marks] (b) When potassium chlorate(V) is heated, it decomposed to release oxygen gas according to the equation  below. 2KClO3 2 KCl + 3O2 (i)  Name a suitable catalyst that can be used to increase the rate of decomposition of potassium chlorate(V) [1 mark] (ii) State 2 characteristics of a catalyst [2 marks] (iii) Contact Process is an industrial process to manufacture sulphuric acid in large scale. State a nd  justify any two of the conditions involved in this process . [4 marks] (c) The graph below shows the change of rate of reaction with time when excess calcium carbonate granules is reacted with dilute hydrochloric acid. State and explain how the rate of reaction changes with time. Rate of reaction

[3 marks]

Time / s

(d) Describe an experiment to study the effect of catalyst manganese(IV) oxide on the rate of  decomposition of hydrogen peroxide. [7 marks] 16.(a)

Diagram 16.1 and 16.2 show energy level diagrams. Energy

Energy

Mg(s) + FeSO4 CaCO3 + 2NaCl ΔH= - 200 kJmol-1

-1

ΔH= + 12.6 kJmol MgSO4 + Fe

Diagram 16.1

(b)

CaCl2 + Na2CO3

Diagram 16.2

(i)

Compare both the energy level diagrams above. Your explanation should include the following  ionic equations type of chemical reactions  energy content of reactants and products [6 marks] 

(ii)

Based on diagram 16.1, calculate the change in temperature of the solution if excess magnesium powder is added to 50 cm 3 of 0.2 mol dm -3 iron(II) sulphate solution. [Given that Specific heat capacity of solution : 4.2 J g -1 oC-1] [3 marks]

Explain why the heat of reaction between 1.0 mole of silver nitrate solution and 1.0 mole of sodium chloride solution is the same as the heat of reaction between 1.0 mole of silver nitrate solution and 0.5 mole of magnesium chloride solution. [4 marks] Chemistry Perfect Score/ X A- Plus Module 2012 51

(c)

A student carried out an experiment to determine the heat of neutralisation for the reaction between 50 cm3 of 2.0 mol dm -3 hydrochloric acid and 100 cm3 of 2.0 mol dm -3 sodium hydroxide solution. The following data was obtained: Initial temperature of hydrochloric acid = 30.2 oC Initial temperature of sodium hydroxide solution = 30.2 oC Highest temperature of the mixture of the solutions = 42.2 oC (i)

Calculate the heat of neutralisation for this reaction. [Given that specific heat capacity of solution = 4.2 J g

-1 o

C -1] [3 marks]

If the experiment is repeated using 100 cm3 of 2.0 mol dm -3 hydrochloric acid and 100 cm 3 of 2.0 mol dm -3 sodium hydroxide solution and all other conditions are the same, predict the increase in temperature. Explain your answer. [4 marks] SECTION C 17. (a) Acid HX is a monoprotic acid while H 2X is a diprotic acid. Both acid HX and H 2X are strong acid. Using suitable examples, explain what is meant by (ii)

(i) diprotic acid (ii) strong acid [ 4 marks ] (b) Table 9 shows the pH value of sodium hydroxide and aqueous ammonia of the same concentration Alkali Sodium hydroxide solutiom Ammonia aqueous solutiom

Concentration / moldm 0.1 0.1

pH 13 11

Explain why sodium hydroxide solution and aqueous ammonia of the same concentration have different  pH value. [ 6 marks ] 3 -3 (c) Describe how to prepare 250 cm of 1.0 mol dm potassium hydroxide starting from solid potassium hydroxide. State the size of volumetric flask used and calculate mass of potassium hydroxide needed. [Relative atomic mass: H, 1; O, 16; K, 39] [ 10 marks ] 18 (a) Salts is widely used in various fields.  Name one example of salt and its uses in each of the following fields: (i) agriculture (ii) food preparation (iii) medicine [6 marks] (b) By using all the chemical substances given bellow and suitable apparatus, describe a laboratory experiment to prepare dry zinc sulphate s alt.   

zinc nitrate solution Dilute sulphuric acid sodium carbonate solution

In your description, include chemical equations involved. [12marks]

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19 Sodium thiosulphate solution reacts with hydrochloric acid to form sulphur,  pungent gas sulphur dioxide, water and salt (a) Write an ionic equation to represent the reaction given in the box above. [2 marks] (b) The rate of the above reaction can be measured based on the mass of sulphur produced. Based on this statement,state the meaning of the rate of reaction. [2 marks] (c) Suggest two factors that can affect the rate of reaction stated above and state the respective effects on the rate of reaction. [4 marks] (d) You are given a conical flask, a piece of white paper and all other common apparatus found in normal school laboratory. Describe an experiment to show the effect of one of the factors that you have given in (b). In your answer, you are required to show how the data obtained can be analysed to help you draw the conclusion for your experiment. [12 marks] 20.

Table 20.1 shows the data from Experiment I and Experiment II that were carried out to study the rate of reaction of magnesium ribbon with two acids, X and Y . Experiment I

II

Reactants Excess of magnesium ribbon and 50 cm3 of acid X 1.0 mol dm -3 Excess of magnesium ribbon and 50 cm3 of acid Y 1.0 mol dm -3 Table 20.1

Products Magnesium chloride and hydrogen gas

Magnesium sulphate and hydrogen gas

(a) (i) State the name of acids X and Y. Write the chemical equation for the reaction of acid X with magnesium. [3 marks] (ii) Calculate the number of mol of acid X or acid Y that react with excess magnesium ribbon. [1 mark] (iii) Based on this experiment what is meant by the rate of reaction? [1 mark] (b) (i) At the same axis, sketch the graph of volume of gas against time for experiment I and experiment II. [2 marks] (ii) Compare the rate of reaction in experiment I and II . Explain your answer based on collision theory. [5 marks] (c) Describe one laboratory experiment to conduct the Experiment I or Experiment II to determine the rate of reaction. Your answer should include the following : A labeled diagram showing the apparatus set-up Procedures of the experiment A table to collect the data [8 marks]

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21

(a)

A student carried out an experiment in the laboratory to determine the heat of precipitation of  silver chloride, AgCl using the following chemical substances : 25 cm3 of 0.5 mol dm -3 silver nitrate solution 25 cm3 of 0.5 mol dm -3 sodium chloride solution Table 21.1 shows the result of the experiment : Initial temperature of silver nitrate, AgNO 3 solution

29.0 oC

Initial temperature of sodium chloride, NaCl solution

29.0 oC

Highest temperature of reaction mixture

33.0 oC

Table 21.1

(b)

(i)

Calculate the heat of precipitation of silver chloride [ Specific heat capacity for all solution is 4.2 Jg -1oC-1and the density of all solution is 1.0 g cm-3]

(ii)

Draw an energy level diagram for the reaction between silver nitrate and sodium chloride. [4 marks]

Table 10.2 shows the heat released for Experiment I, II and III using different acid that has been reacted with sodium hydroxide solution. Experiment

Chemical Equation

Heat released

I

HCl + NaOH → NaCl + H 2O

57

II

CH3COOH + NaOH



54

III

H2SO4 + 2NaOH

Na2SO4 + 2H2O



CH3COONa + H2O

Based on Table 21.2, explain the difference in heat released between : (i) Experiment I and Experiment II (ii) Experiment I and Experiment III (c)

114

[6 marks]

Describe a laboratory experiment to determine the heat of displacement of metal by a more electropositive metal. In your description, include the following aspects :  Materials and apparatus needed  Procedure of experiment  A table to collect data  Calculation method [10 marks]

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22 (a)

(b)

What is meant by exothermic and endothermic reaction? Compare the changes in energy content of the reactants and products for both of the reactions. [4 marks] Diagram represent the energy level diagram for a chemical reaction Energy C

+

D

-3

ΔH= + x kJ mol

A + B

State four information that can be obtained from the above diagram. [4 marks] (c)

Reaction I and II below are the thermochemical equation for the heat of precipitation. -1 Reaction I : AgNO 3 + NaCl → AgCl +  NaNO3  H = - 210 kJmol -1 Reaction II : AgNO3 + KCl → AgCl + K   NO3  H = - 210 kJmol Explain why the value of heat of precipitation in reactions I and II are the same. [4 marks]

d)

2+

Ca (aq) +

2-

CO3 (aq) →

CaCO3 (s)

-1

∆H = + 12.6 kJmol

Describe a laboratory experiment to determine the heat of reaction for the above reaction. In your  answer, include the following : chemicals required    procedures of the experiment  results and calculation involved [8 marks]

23.

The thermochemical equation for the combustion of butanol is given as follows: C4H9OH + 6O 2 

4CO2 + 5H2O

∆H = -2679 kJmol -1

[Relative atomic mass : H=1, C=12, O=16, specific heat capacity of water = 4.2 Jg -1 oC-1] (a)

State three information that can be obtained from the above equation. [3 marks]

(b)

Calculate the mass of butanol that must be burnt to raise the temperature of 400 cm 3 of water   by 25°C. [3 marks]

(c)

Describe an experiment to determine the heat of combustion of butanol. Your answer should include: (i) (ii) (iii) (iv)

apparatus set-up procedure of the experiment data obtained from the experiment calculation of heat of combustion of butanol.

Chemistry Perfect Score/ X A- Plus Module 2012

[2 marks] [6 marks] [2 marks] [4 marks]

55

CHEMISTRY MODULE

SET

1. 2. 3.



Carbon Compounds Manufactured Substances in Industry Chemicals for Consumers

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SECTION A 1.

Diagram 1 shows the structural formula of compound X.

Diagram 1 (a) Compound X is an unsaturated hydrocarbon. What is the meaning of unsaturated hydrocarbon? ......……........……………………………………...................................................................... [2 marks] (b) State the homologous series for compound X. ......................……………………………………...................................................................... [1 mark] (c)  Name the compound X. ......................……………………………………...................................................................... [1 mark] (d) At 180 oC and in the presence of nickel as catalyst, compound X can be changed into saturated hydrocarbon compound. (i) Name the reaction. ......................……………………………………...................................................................... [1 mark] (ii) Draw the structural formula for the compound formed.

[1 mark] (e) Compound X burns completely in excess oxygen. (i) Write a balanced chemical equation for the complete combustion of X. .............................................................................................................................................. [2 marks] (ii) 2.1 g of compound X undergoes complete combustion at room conditions. Calculate the volume of carbon dioxide gas released. [1 mol of gas occupies 24 dm 3 at room conditions; Relative atomic mass: H = 1; C = 12]

[2 marks]

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2.

Diagram 2 shows a series of reactions. Compound P with the molecular formula C 2H6O, can be prepared through fermentation of glucose solution. Glucose Compound P C2H6O

Reaction I

Compound Q Reaction II

Compound R  Diagram 2 (a) Name the compound P. ......………………………………………………………………………................................... [1 mark] (b) State the functional group of compound P. ......………………………………………………………………………................................... [1 mark] (c) In the reaction I, compound Q is produced when an acidified potassium dichromate (VI) solution is added into a test tube containing compound P. (i) Name the reaction I. …………………………………………………………………….................................... [1 mark] (ii) State one observation for this reaction. ...................……………………………………………………………………….............. [1 mark] (iii) Draw the structural formula of compound Q.

[1 mark] (d) In the reaction II, compound R is formed when compound P reacts with compound Q in the  presence of concentrated sulphuric acid. (i) Name the reaction II.

(ii)

……………………......................……………………………………………….............. [1 mark] Name the compound R.

(iii)

…………………………………………………………………….................................. [1 mark] Give one special physical property of compound R.

(iv)

..…………………………………………………………………….................................. [1 mark] Write the chemical equation for the reaction II. …………………………………………………………………........................................ [2 marks]

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3.

Diagram 3 shows a series of reactions involving compound Q, C 2H6O. Glucose

I Water 

+

Gas P

II

Yeast

III

Compound Q, C 2H6O

Combustion

Gas R 

 pieces of porcelain

IV Acidified potassium

manganate(VII) solution

V

Compound S, C2H4O2

Compound T

Concentrated sulphuric acid, refluxed with compound Q. Diagram 3 (a)

(i) State the name of reaction I. …………....………………………………………………………………………………. [1 mark ] (ii) State the name of compound Q. …………………………………………………………………………..........…………… [1 mark ] (iii) Draw the structural formula for compound Q.

[1 mark ] (b)

Write a chemical equation for the complete combustion of compound Q. …………………………………………………………………………………...…………… [2 marks]

(c) (i) State the name of gas R that produced in reaction III. ……………………………………………………………………………....……………. [1 mark ] (ii) Draw the set-up of apparatus to carry out reaction III in the laboratory.

[2 marks] (d) State the change of colour of acidified potassium manganate(VII) solution in reaction IV. ……………………………………………………………………………………………… [1 mark ]

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(e) (i)

State the name of reaction V. …………………………………………………………………………………………. [1 mark ]

(ii) State the name of compound T. …………………………………………………………………………………………. [1 mark ] 4. (a) The following flow chart shows the steps involved in the manufacture of an industrial substance L and the production of fertiliser  M .

(i) What is substance L? ………………………………………………………………………………………………….. [1 mark ] (ii)  Name the industrial process to produce substance L. ………………………………………………………………………………………………….. [1 mark ] iii) What is substance K ? …………………………………………………………………………………………………... [1 mark ] (iv) The conversion of sulphur dioxide to substance M is very slow. Catalyst and high temperature are used to overcome these problems. State the catalyst and the temperature used. …………………………………………………………………………………………………… [2 marks] (v) What is fertiliser  M ? …………………………………………………………………………………………. [1 mark ] (b) Table 4 shows the manufactured substances in industries. Material

Substance L

Alloy

Polymer

Glass

Example

Reinforced concretes

Bronze

Polyvinyl chloride (PVC)

Borosilicate glass

Table 4 Based on Table 4, answer the following questions. (i) State the name of substance L. ………………………………………………………………………………………….. [1 mark ]

(ii) Draw and label the arrangement of atoms in bronze.

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(iii) Write the chemical equation for the polymerisation process of Polyvinyl chloride. ….………………………………………………………………………………………. [1 mark ]

(iv) State one reason for borosilicate glass to use in laboratory glassware. ….………………………………………………………………………………………. [1 mark ] 5. (a) Soap can be prepared from the reaction between oil and concentrated sodium hydroxide. Diagram 5 shows the equation for the reaction.

O CH2

O

C

R  CH2OH

O CH2

O

C

R 

+

3NaOH

O

C

+

CH2OH CH2OH

O CH2

Soap Y

R  Diagram 5

R is a carbon chain with 15 carbon atoms. (i) State what is soap. ………………………………………………………………………………………………….. [1 mark ]

(ii) Draw the structural formula for soap Y formed . On the diagram you have drawn , label the hydrophobic and hydrophilic parts of the soap

[2 marks]

(iii)  Name this reaction ………………………………………………………………………………………………………. [1 mark ]

(iv)

During the preparation of soap, sod ium chloride is added to the soap mixture. Explain why? ………………………………………………………………………………………………… ………………………………………………………………………………………………… [1 mark ]

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(b)

Medicine is often given to patients to cure or prevent diseases. The table below shows the examples of  four types of commonly used medicines. Medicine Example Analgesics Aspirin Q Penicillin Psychotherapeutic medicine  P 

(i) What is the function of analgesics medicines? ………………………………………………………………………..……………………………….. [1 mark ] (ii) What is the negative effect of taking aspirin. ………………………………………………………………………..……………………………….. [1 mark ] (iii) State the type of medicine for Q. ………………………………………………………………………..………………………………. [1 mark ] (iv) Why is it very important to follow the prescription and to complete the dosage when taking  penicillin? ………………………………………………………………………..……………………………….. ………………………………………………………………………..……………………………….. [1 mark ] (v) State one example of  P. ………………………………………………………………………..………………………………… [1 mark ]

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SECTION B

6 (a)

Table 6 shows some information about three members of a homologous series. Member of  homologous series

Boiling point (°C)

Preparation

Oxidation product

Ethanol

78

C2H4 + H2O → C2H5OH

Ethanoic acid

Propanol

97

C 3H6 + H2O → C3H7OH

Propanoic acid

Butanol

118

C 4H8 + H2O → C4H9OH Table 6

Butanoic acid

Based on Table 6, state and explain five characteristics of a homologous series. [10 marks] (b)

The following information is about an organic compound X. Empirical formula is CH2O Relative molecular mass is 60  Reacts with calcium carbonate to produce a type of gas that turns lime water chalky  Based on the information given: 

(i)

State the molecular formula of X. (Relative atomic mass : C = 12, H = 1, O = 16) [2 marks]

(ii)

State the name of the homologous series for X and explain your answer. [2 marks]

(iii)

(c)

Write a balanced chemical equation for the reaction of compound X with calcium [2 marks] carbonate.

Diagram 6 shows the structural formulae of hydrocarbon of compounds P and Q.

Compound P

Compound Q

Diagram 6 Compare and contrast these two hydrocarbons based on their structures. [4 marks] 7.

(a)

A hydrocarbon M, consists of 85.7% of carbon and X% of hydrogen by mass. [Relative atomic mass: C = 12; H = 1 , Relative molecular mass of M = 56.] (i)

What is the value of X. [1 mark ]

(ii)

Determine the empirical formula and molecular formula of hydrocarbon X. [5 marks]

(iii)

Draw the structural of the two isomers of hydrocarbon M. Write the names for each isomer  [4 marks]

(iv)

Compound M burns with sootier flames as compared to butane. Explain and prove.

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(b)

Natural rubber is a natural polymer. (i) Give another two examples of natural polymer. [2 marks] (ii)

Name and draw the structural formula of the monomer of natural rubber. [2 marks]

(c)

The tyres of aircrafts are made from vulcanised rubber. (i) What is vulcanised rubber? [1 marks] (ii)

Explain why vulcanised rubber is more elastic than unvulcanised rubber. [2 marks]

8

(a)

Diagram 8.1 shows the structural formula of two of hydrocarbons.

Hydrocarbon A

Hydrocarbon B

Diagram 8.1 (i)

(ii)

(iii)

(iv)

State the type of bond, homologous series and general formula of hydrocarbon A and hydrocarbon B. [6 marks] Complete combustion of hydrocarbon A produces gas C and water. State the name of gas C and write the chemical equation for the reaction. [3 marks] Which hydrocarbon change the colour of bromine water from brown to colourless. Explain your answer. [3 marks] Diagram 8.2 shows the burning of hydrocarbon A and hydrocarbon B in air.

Soot Filter paper 

Porcelain dish Hydrocarbon A

Hydrocarbon B Diagram 8.2

Compare the sootiness of hydrocarbon A and hydrocarbon B. Explain your answer. [Given that the relative atomic mass of H = 1, C = 12] [4 marks]

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(b)

Diagram 8.3 shows the reaction between carboxylic acid X and alcohol Y.

Carboxylic acid X

+

Alcohol Y

+

Water 

Diagram 8.3 Draw the structural formula and state the name of carboxylic acid X and alcohol Y. [4 marks] 9. (a) Sulphur dioxide, SO2, is one of the by-products of the Contact Process. It can cause environmental pollution like acid rain.

Sulphur dioxide gas dissolves in rain w ater to produce sulphurous acid (i) Write the chemical equation for the reaction between sulphur dioxide gas and rain water. (ii) State three effects of acid rain to the environment. [4 marks] (b) Diagram 7 shows an industry preparation of sulphuric acid by the Contact Process. Stage I S

SO2 Oxygen

Stage III

Stage II SO3 Oxygen

Stage IV X

Concentrated sulphuric acid

H2SO4 Water 

Diagram 9 (i)  Name the compound X. (ii) Write the chemical equation of the reaction at stage II. (iii) The chemical equation below shows t he reaction between sulphur and oxygen gas at stage I. S + O2  SO2 Given that the relative atomic mass of S = 32, O = 16 and the molar volume of any gas is 24 dm3mol-1 at room temperature and pressure. Calculate the maximum volume of sulphur diox ide gas produced if 48 g of sulphur is burnt completely in oxygen gas. [6 marks] (c) Brass is an alloy of copper. Pure copper is ductile and malleable whereas brass is s tronger and harder  than copper. (i) Explain why pure copper is ductile and malleable? [5 marks] (ii)  Name the element which is added to copper to make brass. Explain why brass is strong and harder  than copper. Draw a diagram to show the arrangement of atoms in brass. [5 marks]

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10. (a) Food preservatives are substances added to food so that the food can be kept for longer periods for time. Using two suitable examples, explain how they work as preservative.

[4 marks] (b) The following is the information about a child.  2 years old 

High fever 



Whooping cough

(i) Can aspirin be used to treat the child? Explain why. (ii)  Name two examples of modern medicine that can be used to treat the child .

[2 marks] [2 marks]

(iii) Explain the effect if the precautions states in (b)(ii) are not followed properly. [2 marks] (c ) Table 10 shows the food additives that are added to a certain food by two chefs. Chef Wan Turmeric Sugar, salt and spice Garlic

Chef Koh Tartrazine Monosodium glutamate Ascorbic acid Table 10

Based on Table 10, categorise the food additives. Include in your answer the function of each type of food additives and the disadvantages of using any two food additives. [10 marks]

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SECTION C 11.

(a)

Table 11 shows the result of two sets of experiment to investigate the coagulation of latex. Set I II

Type of solution

Observation

Latex + solution X Latex + solution Y

Latex coagulate very fast Latex does not coagulate Table 11

(i)

Suggest one possible substance for solution X. and Y [2 marks]

(ii)

Explain the process of coagulation of latex in set I [4 marks]

(iii)

Explain why latex does not coagulate in set II [2 marks]

(b)

Diagram 11 shows how compound Q is formed from alkene W.

Alkene W + H 2O

Compound Q Diagram 11

(i)

Name the homologous series of compound Q. [1 mark]

(ii)

State two chemical properties of compound Q. [2 marks]

(iii)

By using a compound Q with number of carbon atom per molecule more than one, describe an experiment to convert compound Q to alkene. Your answer should consist of the following: Procedure of the experiment   A labelled diagram showing the apparatus set-up The test to confirm the product is alkene  [9 marks]

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67

12.

Diagram 12.1 shows five structural formula of carbon compound.

Diagram 12.1 (a)

(b)

(c)

Choose any one of the compound in Diagram 12.1, state the products formed when the compound burn completely in excess oxygen gas. Write the chemical equation involve. [3 marks] State the name of two compounds in Diagram 12.1 that are isomer. Explain your answer. [3 marks] Describe a chemical test to differentiate between compound A and compound B. [4 marks]

(d)

Diagram 10.2 shows the reaction between compound E and carboxylic acid. Compound E

+

Carboxylic acid

→

ester 

Diagram12.2 (i)

(ii)

State the name an example of a member of carboxylic acid and state the name of  ester that formed when the named carboxylic acid react with compound E. Draw the structural formula of named carboxylic acid and ester that formed. [4 marks] Describe an experiment to produce ester in (d) (i) in laboratory. [6 marks]

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13

(a)

Diagram 13.1 shows a structural formula of butene,

H

H

H

H

H

C

C

C

C

H

H

H

Diagram 9.1 Draw structural formulae for another two isomers of b utene and names each isomer according to the IUPAC nomenclature. [4 marks] (b)

Diagram 9.2 shows the structural formula of an ester 

H

H

H

O

C

C

C

H

H

O

H

H

C

C

H

H

H

Diagram 13.2 Based on diagram 13.2: (i)

Identify the two organic chemicals needed to produce the ester above. [2 marks]

(ii)

State three chemical properties for each organic chemicals that you stated in 9(b)(i). [6 marks]

(c)

Diagram 13.3 shows the formula of two hydrocarbons P and Q : CH3(CH2)4CH3

CH3(CH2)3CH = CH2

P

Q Diagram 13.3

(i) (ii)

State the name of hydrocarbons P and Q. Describe two chemical tests to differentiate between hydrocarbon P and Q. Your description must include the procedure and observation. [8 marks]

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69

14

Diagram 14 shows the industrial manufacture of ammonia.

Diagram 14 (a) State the name of the above process, catalyst Y and write a chemical equation for the reaction between hydrogen and nitrogen. [4 marks] (b) Table 14 shows the diameter of the dent formed in an experiment to compare the hardness of  copper and bronze. Material Copper  Bronze

Diameter /cm 1.0 0.5 Table 14

Based on Table 12, draw a diagram to shows the arrangement of atoms in pure copper and  bronze. Compare the hardness between copper and bronze and explain why. [6 marks] (c) The iron window frame of Encik Razali’s house rusts after several years but the steel window frame of Encik Tarmizi’s house does not rust. By using suitable examples, describe a laboratory experiment to compare the resistant to rust of  alloy compared to pure metal. Include the following in your answer: Procedure  

Results



Conclusion [10 marks]

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70

15.

(a) Table 15 shows the different types of traditional medicine and modern medicine.

Traditional medicine

Garlic Lemon Ginseng

Quinine Aloe vera Tongkat Ali

Modern medicine

Aspirin Paracetamol Chloropromazin

Penicillin Codein Caffeina

Table 13 (i) What are the differences between traditional medicine and modern medicine? [2 marks] (ii) Modern medicines can be classified as analgesics, antibiotics and psychotherapeutic drugs. Group the medicines in Table 2 into these three different classes. [5 marks] (iii) State the side effects of penicillin, codeine and aspirin. [3 marks] (b) State what is hard water and give an example of hard water. You are required to carry out a laboratory activity to investigate the effectiveness of  cleansing action of soap and detergent in hard water. Your answer should consist of the following:   

Procedure Observation Conclusion [10 marks]

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CHEMISTRY MODULE

SET 5

1. PAPER 3 SET 1 2. PAPER 3 SET 2 3. PAPER 3 SET 3 4. PAPER 3 SET 4 5. PAPER 3 SET 5

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PAPER 3 SET 1 1.

Diagram 1.1 shows the set-up of apparatus for an experiment to compare the hardness of a metal and its alloy. Thread Weight

Meter ruler  Retort stand

Steel ball  bearing

Copper block  Diagram 1.1

A steel ball bearing is taped onto the copper block using cellophane tape. A weight of 1 kilogram is dropped at a height of 50 cm to hit the ball bearing. The diameter of the dent made on the copper block is measured. The experiment is repeated by replacing copp er block with bronze block. Table 1.1 shows the view of the dents made on bronze and copper block  Experiment

Bronze

Copper 

I

Diameter: .............

Diameter: .................

II

Diameter: .................

Diameter: .................

III

Diameter: .................

Diameter: ................. Table 1.1 (a) (i)

By using the ruler given, measure the diameters of the dents made on copper and  bronze blocks. Record all the diameters of the dents in Table 1.1. [3 marks]

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(ii)

Construct a table to record the diameters of the dents and average diameter of the dent on copper and bronze blocks.

[3 marks] (b) State one observation that can be obtained from this experiment. .......................................................................................................................................... ………………………………………………………………………………..………… [3 marks] (c) Based on the average diameter of the dents on copper and block, state the inference that can be made. .......................................................................................................................................... ………………………………………………………………………………………… [3 marks] (d) State the operational definition of the hardness of bronze. .......................................................................................................................................... ………………………………………………………………………………………… [3 marks] (e) Explain why there is difference in diameter of dents on copper and bronze blocks. .......................................................................................................................................... ………………………………………………………………………………………… [3 marks] (f) State the hypothesis for this experiment. .......................................................................................................................................... ..………………………………………………………………………………………… [3 marks] (g) Complete table 1.2 based on the experiment.  Name of variables (h) Manipulated variable:

Action to be taken (i)The way to manipulate variable:

(ii) Responding variable:

(ii) What to observe in the responding variable:

(iii) Controlled variable:

(iii) The way to maintain the control variable:

Table 1.2

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2. The table 2.1 below shows the set-up of apparatus of the experiment to investigate the effect of copper, magnesium and zinc on the rusting of iron. A mixture of jelly solution, potassium hexacyanoferrate(III) solution and phenolphthalein were used as med ium in each test tube. The observations were recorded after one day.

Test tube A Iron nail coiled with copper 

High intensity of blue colour.

Test tube B Iron nail coiled with magnesium

High intensity of   pink colour 

Test tube C Iron nail coiled with zinc

Low intensity of   pink colour 

Test tube D Iron nail

Low intensity of   blue colour 

Table 2.1 (a) State the inference for the observation in test tube A, B, C and D. Test tube

Inference

A B C D [3 marks] (b) Based on this experiment, explain why there is a difference in the observation between test tube A and test tube B. ………………………………………………………………………………………… .………………………………………………………………………………………. [3 marks]

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(c) State the hypothesis for the experiment. …………………………………………………………………………………………. …………………………………………………………………………………………. [3 marks] (d) Based on this experiment state: (i) The manipulated variable: …..……………………………………………………………………………......... (ii) The responding variables: ………………………..……………………………………………………………… (iii) The constant variables: …………………………….………………………………………………………….. [3 marks] (e) State the operational definition for the rusting of iron nail. ……………………………………………………………………………………………… ………………………………………………………………………………………………[3 marks] (f) Based on this experiment classify the metals that can provide sacrificial protection and metal cannot  provide sacrificial protection to iron.

[3 marks] (g) Observation in test tube D is recorded after two days After one day

After two days

Compare the observation for the experiment in the first day and the second day Explain your answer. …………………………………………………………………………………………. …………………………………………………………………………………………. [3 marks]

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ESAY / PLANNING 3.

Different type of alcohols produces different heat of combustions when burnt in oxygen. When the number of carbon per molecule of alcohol increases, the heat of combustion also increases. Table 3.1 shows the heat of combustion of ethanol, propanol and butanol. Alcohol Ethanol Propanol Butanol

Molecular formula C2H5OH C3H7OH C4H9OH

Heat of combustion/ kJ mol-1 -1376 -2016 -2678

Table 3.1 Plan a laboratory experiment to investigate the relationship between type of alcohols and the heat of combustion  produced. Your planning must include the following aspects: (a) Statement of the problem (b) All the variables (c) Hypothesis (d) List of materials and apparatus (e) Procedure (f) Tabulation of data [17 marks] PAPER 3 SET 2 1.

A student carried out an experiment to determine the end-point for the titration of 25.0 cm 3 of 1.0 mol dm-3 sodium hydroxide solution with hydrochloric acid. Phenolphthalein is used as the acid-base indicator. Table 1 shows the three titrations that were conducted and the magnification of the burette readings.

Titration No.

I

II

III

13

Initial burette reading

1

hydrochloric acid

hydrochloric acid

26

hydrochloric acid

14 27

2

………………………..

…………………………..

38

13

Final burette reading

……………………………..

hydrochloric acid

hydrochloric acid

26

hydrochloric acid 39

14 27

…..……………………

….……………………

…..…………………….

Table 1

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(a)

Record the burette readings for the three titrations in the spaces provided in Table 1.

[3 marks] (b) Construct a table and record the initial burette reading, final burette reading and the volume of acid used for each titration.

[3 marks] (c) Calculate the molarity of the hydrochloric acid used in the experiment.

[ 3 marks] (d) The experiment is repeated by replacing hydrochloric acid 1.0 mol dm -3 with sulphuric acid 1.0 mol dm -3. (i)

Predict the volume of sulphuric acid needed to neutralise the sodium hydroxide solution. ..............................................................................................................................

(ii) Explain your answer for (d) (i). ……...................................................................................................................... ……...................................................................................................................... [3 marks]

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(e) Table 1 shows the results of an experiment to investigate the relationship between the pH values of  acids and the strength of acid. Solution pH value -3 Hydrochloric acid, 1.0 mol dm 2.0 -3 Ethanoic acid, 1.0 mol dm 5.0 Table 1 For this experiment, state (i) The manipulated variable .......................................................................................................................................... (ii)The responding variable ……........................................................................................................................... ....... (iii) The fixed variable …….................................................................................................... .............................. [3 marks] (g) State one hypothesis for this experiment. ………………………………………………………………………………………………………………

……………………………….………………………………………………………………………………………… [3 marks] (h) Classify the following substances into substances with pH value less than 7 and pH value more than 7. Ethanoic acid Ammonia solution

Barium hydroxide Nitric acid

[3 marks]

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2.

Diagram 2.1 shows the apparatus set up for the preparation of ester in the laboratory.

water in

water out

heat

Mixture of alchohol + carboxylic acid and a few drops of  concentrated sulphuric acid

Diagram 2.1 Table 2.1 show some examples of the types of alcohol and carboxylic acid used to prepare ester. Alcohol Methanol Ethanol Propanol

Carboxylic Acid Ethanoic acid Propanoic acid Methanoic acid

Observation Sweet pleasant smell Sweet pleasant smell Sweet pleasant smell Table 2.1

(a) State one inference for this experiment. ……………………………………………………………………………………………………… ………………………………………………………………………………………………………… …………………………………………………………………………………………………….… [3 marks] (b) Construct a table to show the name of the esters formed from the alcohols and carboxylic acids  provided in Table 2.1

[3 marks] (c) Propyl butanoate is an ester that is formed from the reaction between an alcohol and carboxylic acid.  Name the alcohol and carboxylic acid needed to prepare the ester. Alcohol: .................................................................................................................................... Carboxylic acid: ......................................................................................................................................................... [3 marks] Chemistry Perfect Score/ X A- Plus Module 2012

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(d) Table 2.2 shows the observation for an experiment to differentiate between alkanes and alkenes.

Experiment With bromine water

Hexane No change

With acidified potassium manganate (VII) solution

 No change

Hexene Brown bromine decolourised Purple solution decolourised

Table 2.2 (i)

State the variables for this experiment: Manipulated variable: ………………............................................................................................. Responding variable: …………………………................................................................................ Fixed variable: ……........................................................................................................................ [3 marks]

(ii)

State one hypothesis for this experiment. ….………………………………………………………………………………… …...………………………………………………………………………………… [3 marks]

(iii)

Hexene can also be differentiated from hexane with sootiness of flame when burnt. Predict which substance will produce more soot when burnt. Explain your answer. ….…………………………………………………………………………………

…………………………………………………………………………………… [3 marks]

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3. Diagram 3 shows the set-up of apparatus used to investigate the cleansing action of soap and detergent on a piece of cloth stained with oil.

Based on the above diagram, plan one laboratory experiment tocompare the effectiveness of soap and detergent in hard water. Your planning should include the following aspects: (a) (b) (c) (d) (e) (f)

Problem statement All the variables Statement of the hypothesis List of substances and apparatus Procedure of the experiment Tabulation of data [17 marks] END OF QUESTION PAPER 

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SET 3 1. Diagram 1.1 shows the set-up of apparatus and thermometer reading for the experiment to compare the heat of combustion of four alcohols, methanol (CH3OH), ethanol (C2H5OH), propanol (C 3H7OH) and  butanol (C4H9OH). The initial and final mass of the spirit lamp containing alcohol is weighed and recorded. The alcohols is used to heat 200 cm 3 of water .

Wind shield

Thermometer  Copper tin Water 

Methanol

Initial temperature:......................... Wind shield Thermometer 

Co

er tin Water 

Methanol

Diagram 1.1

Highest temperature:...................

(a) Based on Diagram 1.1, (i) Record the initial and highest reading of the thermometer in the spaces provided. [3 marks] (ii) State one observation .......................................................................................................................................................[3 marks] (iii) Give one inference based on the observation in (a)(ii). .......................................................................................................................................... [3 marks]

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(b) Diagram 1.2 shows the initial and final reading of the electronic balance for the mass of spirit lamp  before burning and after burning of four alcohols. Alcohol

Initial reading (g)

Final reading (g)

Mass of alcohol used (g)

Methanol ON OFF

354.9548 g

ON OFF

353.4012 g

Ethanol OFF ON

342.0201 g

ON OFF

339.7892 g

Propanol ON OFF

364.4303 g

ON OFF

360.8702 g

Butanol ON OFF

332.9891 g

ON OFF

328.9790 g

Diagram 1.2 Based on Diagram 1.2, (i) State the mass of the alcohols used in space provided into two decimal places. [ 3 marks] (ii) Tabulate the initial mass, final mass and mass of alcohol used for the four alcohols in this experiment.

[3 marks] (c) Calculate the heat of combustion of methanol. [Specific heat capacity of water = 4.2 J g-1 oC-1]

[3 marks] Chemistry Perfect Score/ X A- Plus Module 2012

84

(d) Table 1.1 shows the heat of combustion of ethanol (C 2H5OH), propanol (C 3H7OH) and butanol (C4H9OH). Alcohol Molecular Formulae Heat of combustion/kJ mol -1 Ethanol C2H5OH 970 Propanol C3H7OH 1400 Butanol C4H9OH 1860 Table 1.1 For this experiment, state: (i) The manipulated variable................................................................................. The responding variable..................................................................................... The fixed variable............................................................................................... [3 marks] (ii) State one hypothesis for this experiment. ................................................................................................................................................. ................................................................................................................................................. ................................................................................................................................................. [3 marks] (e) If the experiment is repeated using pentanol, predict the heat of combustion of pentanol. ................................................................................................................................................. [3 marks]. (f) The actual heat of combustion for ethanol is 1376 kJ mol-1. State three reasons why the experimental value heat of combustion for ethanol is less than the actual value. 1. .................................................................................................................................... 2. .................................................................................................................................... 3. .................................................................................................................................... [3 marks] (g) Table 1.2 shows the list of carbon compounds and their molecular formula. Carbon compound

Molecular formula

Hexene

C6H12

Propanoic acid

C2H5COOH

Ethanol

C2H5OH

Methane

CH4 Table 1.2

Classify the above carbon compounds into hydrocarbon and non hydrocarbon.

[3 marks] Chemistry Perfect Score/ X A- Plus Module 2012

85

2. Diagram 2.1 and 2.2 show Experiment I and Experiment II to investigate the effect of type of electrodes on the products formed at the electrodes. Experiment I

After 30 minutes Carbon

Carbon electrodes

Diagram 2.1 Experiment II

After 30 minutes

Copper electrodes 0.01 mol dm - copper(II) chloride solution Diagram 2.2 Based on Diagram 2.1 and Diagram 2.2 above, plan a laboratory experiment to investigate the effect of the type of electrode to the product at anode. Your answer should consist of the following: (a) Aim of experiment (b) All the variables (c) Hypothesis (d) List of materials and apparatus (e) Procedure (f) Tabulation of data [17 marks]

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SET 4

1.

The experiment is carried out using a small piece of lithium and potassium to react with set-up of apparatus and observations of reaction are shown in Table 1.1 Set

Set-up of apparatus

oxygen gas. The

Observation

White fumes Burns slowly and produces white fumes.

I

Lithium

White fumes II

Potassium

Table 1.1

(a)

Complete the Table 1.1 by stating the observation for reaction of potassium metal towards oxygen. [3 marks]

(b)

Based on the Table 1.1, state the relationship between the positions of element of Group 1 with the reactivity of the elements towards oxygen gas. ………………………………………………………………………………….…………..…… …………………………………………………………………………………….……………. [3 marks]

(c)

After the reaction in Set I stopped, the gas jar is filled with water and a few drops of   phenolphthalein solution is added. The colourless solution formed change to pink. Give one inference based on the observation above. …………………………………………………………………………………….......... [3 marks]

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(d)

The experiment is repeated by using X metal to react with oxygen. The result of the experiment is shown in Table 1.2.

Set-up of apparatus

Observation on the metal

White fumes

Burns rapidly and produces white fumes.

X metal

Table 1.2

Predict the position of X metal in the Periodic Table of elements. ………………………………………………………………………………….……… …………………………………………………………………………………….……. [3 marks] (e)

Lithium hydroxide solution is produced when lithium oxide reacts with water. Classify the ions that exist in the solution i nto cation and anion. Cation

Anion

[3 marks]

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2.

An experiment was carried out to construct an electrochemical series of metals. Diagram 2.1 shows the set-up apparatus for an experiment the chemical cell to measure the potential difference between electrode Copper metal and metal M. An experiment was repeated by replacing metal M with metal J and Q.

V

copper metal

metal M

Copper( II ) sulphate solution 1.0 mol dm -3

Diagram 2.1

1.5 0.5 0

1.5

2.0

1.0

·

2.0

1.0 2.5

0.5

3.0

0

V

·

A

1.5 1.0

C

B

2.5

·

0

3.0

2.0

V

0.5

2.5

3.0

Diagram 2.2

Diagram 2.2 shows the potential difference of three voltmeters A, B and C fo r the chemical cells with pair  of metal Cu/M, Cu/J and Cu/Q respectively. i) Pair of Metals

Voltmeter

Cu and M Cu and J Cu and Q

A B C

Potential difference(V)

Positive terminal Cu Cu Q

Table 1

(a)

Record the voltmeter reading for the pairs of metal in the Table 1. [ 3 marks]

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(b) State the hypothesis of the experiment ................................................................................................................................................................. ........................................................................................................................................... [ 3 marks ] (c)

Arrange J, Cu, M and Q metals in the descending order in the electrochemical series ........................................................................................................................................... [ 3 marks ]

(d)

Iron metal is located between metal M and copper metal in the electrochemical series. State which metals are more electropositive and less electropositive than iron metal. More electropositive than iron: ........................................................................................................................................... Less electropositive than iron ......................................................................................................................................... [3 marks]

(e)

Diagram 2.2 below shows simple voltaic cell using Cu and metal J before and after an experiment. V

Copper

Metal J

Copper(II) sulphate Solution (blue colour)

Before experiment V

Copper 

Metal J Copper(II) sulphate Solution (light blue) After experiment Diagram 2.3

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State three observations shown in Diagram 2.3 1. ……………………………………………………………………………………...... 2. …………………………………………………………..…………………………… 3. …………………………………………………………..…………………………… [3 marks] 3.

Reaction between sodium thiosulphate, Na 2S2O3 solution and dilute sulphuric acid, H2SO4 will produce sodium sulphate, Na 2SO4, sulphur, S, sulphur dioxide, SO 2 and water, H2O. The chemical equation is:

 Na2S2O3 + H2SO4  Na2SO4 + S + SO2 + H2O

By using the information above, plan an experiment to investigate the effect of temperature on the rate of  reaction. Your planning should include: Your planning should include the following aspects: (a) (b) (c) (d) (e) (f)

Problem statement All the variables Statement of the hypothesis List of substances and apparatus Procedure of the experiment Tabulation of data [17 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

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SET 5

1. Diagram 1.1 shows the conversation between a student and his teacher.

Diagram 1.1 Based on Diagram 1.1, an experiment was carried out using glacial ethanoic acid and ethanoic acid in two different solvents. Table 1 shows the results of the experiment when tested with blue litmus  paper. Experiment

State of ethanoic acid

I II III

Glacial ethanoic acid Ethanoic acid in water Ethanoic acid in dry propanone,

Observation on blue litmus paper  No change Blue to red No change

Table 1 (a) State one inference for this experiment. .......................................................................................................................................... ......................................................................................................................................... ......................................................................................................................................... [3 markah] (b) Explain the difference in observation for Experiment II and III. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... [3 mark] (c) Based on the experiment, state Manipulated variable: ........................................................................................................................................ Responding variable: ……………………........................................................................................................ Fixed variable: ………………................................................................................................................. [3 marks] Chemistry Perfect Score/ X A- Plus Module 2012

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(d) State one hypothesis for this experiment. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... [3 marks] (e) Diagram 1.2 shows the experiment to investigate which solvent can cause an alkali to exhibit its alkaline properties. I

(i)

II

III

.Diagram 1.2 State the observation in Diagram 1.2. Test tube I: ............................................................... Test tube II: ............................................................. Test tube III: ...........................................................

(ii)

[3 marks]

Construct a table to record the observation for experiment I, II and III.

[3 marks] (f) Classify the following substances into substances that can change moist blue litmus paper to red and substances that can change moist red litmus paper to blue. Calcium hydroxide Oxalic acid Ammonia aqueous

Phosphoric acid Barium hydroxide Sulphurous acid

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2. Diagram 2 shows Step I and Step II in an experiment to construct a n ionic equation for the formation of barium chromate(VI).

Step I:

5 cm

5 cm

5 cm

5 cm

5 cm

5 cm

5 cm

-

0.5 mol dm  potassium chromate (VI) solution

Step II: 1 cm

2 cm

3 cm

4 cm

5 cm

6 cm

7 cm

0.5 mol dm  barium chloride solution

Yellow precipitate Diagram 2

-3

3

0.5 mol dm barium chloride, BaCl 2 solution was added to each test tube containing 5.0 cm  potassium chromate(VI), K 2CrO4 solution according to the volumes shown in Step II. Each test tube is stopper and shaken well. Yellow precipitate of barium chromate(VI) is formed.

Chemistry Perfect Score/ X A- Plus Module 2012

94

Table 2 shows the results for this experiment. Test tube

1

2

3

4

5

6

7

1.0

2.0

3.0

4.0

5.0

6.0

7.0

-

Volume of 0.5 mol dm  barium chloride solution/cm3 Height of barium chromate (VI) precipitate/cm

Table 2

(a) Using a ruler, measure the height of yellow precipitate in test tube 1 to 7 and record the height of the precipitate in Table 2. . [3 marks] (b) Draw a graph of height of precipitate against volume of barium chloride on the graph paper   provided. [3 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

95

Question 2(b)

Chemistry Perfect Score/ X A- Plus Module 2012

96

(c) Based on the graph above, state the volume of barium chloride solution 0.5 mol dm -3 which 3 react completely with 5 cm of potassium chromate(VI) solution and calculate the number of  mole of barium chloride solution is needed to react completely with 1 mole potassium chromate(VI) solution.

[3 marks] (d) Write an ionic equation for the reaction between potassium chromate(VI) solution and barium chloride solution. ………………………………………………………………………………………….. [3 marks] (e) State the operational definition for the precipitation of barium chromate(VI)

………………………………………………………………………………………….. ………………………………………………………………………………….............. ………………………………………………………………………………………….. [3 marks] (f) Classify the following salts into soluble salts and insoluble salts. .

Sodium carbonate, Na 2CO3 Silver chloride, AgCl

Soluble salts

Lead(II)sulphate, PbSO4 Magnesium nitrate, Mg(NO 3)2

Insoluble salts

[3 marks]

Chemistry Perfect Score/ X A- Plus Module 2012

97