03_Chemistry.pdf

IITJEE CHEMISTRY SAMPLE PAPER – IV Data required : Atomic Number : Cu = 29

SECTION – I Straight Objective Type This section contains 8 multiple choice questions numbered 1 to 8. Each question has 4 choices (a), (b), (c) and (d), out of which ONLY ONE is correct.

1.

Select correct statement : (a) Acidic strength of HBr > HCl but reverse is true for their reducing property. (b) Basic strength of PH3 > AsH3 but reverse is true for their Bond angle. ˆ H bond angle. (c) Dipole moment of CH3Cl > CH3F but reverse is true for their HC (d) Ka1 of fumaric acid is higher than maleic acid but reverse is true for their Ka2.

2.

Which one of the following compounds does not give positive test for nitrogen in the Lassaigne’s test? (a) Urea (b) Hydroxyl amine (c) Glycine (d) Diethylamine

3.

In methyl alcohol solution, bromine reacts with ethene to yield BrCH2CH2OCH3 in addition to 1, 2-dibromoethane because (a) the methyl alcohol solvates the bromine. (b) the ion formed initially may react with Br or CH3OH. (c) this is a free radical reaction. (d) the reaction follows Markovnikov’s rule.

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4.

Compound (A) C6H12O3, when treated with I2 in aqueous sodium hydroxide gives yellow precipitate. When (A) is treated with Tollen’s reagent no reaction occurs. When (A) is hydrolysed and then treated with Tollen’s reagent, a silver mirror is formed in test tube. Compound (A) will be O OCH3 O (b) CH3–C–C–CH3

(a) CH3–C–CH2–CH2–CH–OH

OCH3

OCH3

O

O

(c) CH3–C–CH2–CH(OCH3)2

(d) H–C–CH2–CH2–CH(OCH3)2

5.

A compound ‘X’ on heating gives a colourless gas. The residue is dissolved in water to obtain ‘Y’. Excess CO2 is passed through aqueous solution of ‘Y’ when ‘Z’ is formed. ‘Z’ on gentle heating gives back ‘X’. The compound ‘X’ is : (a) NaHCO3 (b) Na2CO3 (c) Ca(HCO3)2 (d) CaCO3

6.

When the applied voltage is 10,000 V, the de-Broglie wavelength of an electron is (Planck’s constant: h = 6.626 × 10–34 Js , Mass of electron me : = 9. 1 × 10–31Kg) (a) 0.0123 Å (b) 12.3 Å (c) 0.123 Å (d) 1.23 Å

7.

Two solid compounds X and Y dissociate at a certain temperature as follows X(s) A(g) + 2B(g); K P = 9 10–3 atm3 1

Y(s)

2B(g) + C(g); K P = 4.5 2

10–3 atm3

The total pressure of gases over a mixture of X and Y is : (a) 4.5 atm (b) 0.45 atm (c) 0.6 atm (d) none of these 8.

In fcc lattice, A, B, C, D atoms are arranged at corner, face center, octahedral void and tetrahedral void respectively, then the body diagonal contains : (a) 2A, C, 2D (b) 2A, 2B, 2C (c) 2A, 2B, D (d) 2A, 2D

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SECTION II Reasoning Type This section contains 4 reasoning type questions numbered 9 to 12. Each question contains Statement-1 and Statement-2. Each question has 4 choices (a), (b), (c) and (d), out of which ONLY ONE is correct. Directions: Read the following questions and choose (A) Statement-1 is True, Statement-2 is True ; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True ; Statement-2 is not a correct explanation for Statement-1. (C) Statement-1 is True, Statement-2 is False. (D) Statement-1 is False, Statement-2 is True. 9.

Statement-1: [Cu(NH3)4]2+ complex has tetrahedral geometry. Statement-2: This complex is paramagnetic having an unpaired electron in 4p-orbital. (a) A

10.

(b) B

(c) C

(d) D

Statement-1: n-butane is the smallest hydrocarbon which on monochlorination gives an enantiomeric mixture. Statement-2: Synthesis of chiral compounds from achiral reactants always yields the racemic modification. (a) A

11.

(b) B

(c) C

(d) D

Statement-1: Cleavage of optically active sec-butyl methyl ether by anhydrous HBr yields chiefly methyl bromide and sec. butyl alcohol with retention of configuration. Statement-2: Cleavage of this ether occurs through SN1 pathway. (a) A

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(b) B

(c) C

(d) D

12.

Statement-1: A rise in temperature from 250 to 300°C, increases the rate by greater amount for a reaction with Eact = 5 kcal, than the reaction with Eact = 15 kcal. Statement-2: The greater the Eact, the greater the effect of a given change in temperature on the value of rate. (a) A

(b) B

(c) C

(d) D

SECTION III Linked Comprehension Type This section contains 2 paragraphs C13 C18. Based upon the paragraph, 3 multiple choice questions have to be answered. Each question has 4 choices (a), (b), (c) and (d), out of which ONLY ONE is correct. Passage–I The electrochemical series is the arrangement of various electrode systems in the increasing order of their standard reduction potentials. It has several important features. On moving from the top to the bottom in the series, tendency to gain electrons, i.e., to get reduced increases. The electrode systems having negative values of standard reduction potentials act as anode when connected to a standard hydrogen electrode, while those having positive values act as cathode. 13.

HCl can not be stored in an aluminium vessel because (a) E 0Al3 / Al is much smaller than E 0H / H . 2

(b) Al is a highly reactive metal. (c) HCl is an oxidizing acid. (d) All of these 14.

If E 0Cu 2

/ Cu

0.34 V and E 0Ag

/ Ag

= 0.8 V, predict whether the reaction given below is feasible

or not? Cu2+ (aq) + 2Ag(s) Cu(s) + 2Ag+ (aq) (a) Feasible. (c) Feasible at high temp.

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(b) Not feasible. (d) Feasible on increasing the conc. of Ag+(aq).

15.

If E 0Fe2

/ Fe

0.44 V and E 0Mg 2 / Mg

2.37 V, E 0Cu 2

/ Cu

0.34 V and E 0Ag

/ Ag

0.80 V, the

correct order in which the metals displace each other is (a) Ag > Cu > Fe > Mg (b) Fe > Cu > Ag > Mg (c) Fe > Ag > Cu > Mg (d) Mg > Fe > Cu > Ag Passage–II Amines can be produced by selective reduction of nitro compounds. A mixture of (Sn + HCl) acts as a good reducing agent which converts nitro benzene to aniline. Diazotisation takes place when aniline is treated with a mixture of NaNO2 and conc. HCl. A large number of aromatic compounds can be prepared from diazonium salt e.g. on hydrolysis it produces a hydroxyl group. 16.

Nitration of aniline in strongly acidic medium, results in the formation of m-nitroaniline also. This is because (a) Amino group is meta orienting during electrophilic substitution reaction. (b) Nitro group goes away to the meta position irrespective of the substituents. (c) Nitration of aniline is a nucleophilic substitution reaction in strongly acidic medium. (d) In strongly acidic solution aniline is present as anilinium ion.

17.

Identify the product in the following sequence NH2 (i) NaNO2/conc. HCl (0–5°C)

Br

Br

(ii) H3PO2

Br (a) 3, 4, 5-tribromobenzene (c) 2, 4, 6-tribromobenzene

18.

?

(b) 1, 2, 3-tribromobenzene (d) 3, 4, 5-tribromophenol

Electrolytic reduction of nitrobenzene in weakly acidic medium gives: (a) N-phenyl hydroxyl amine (b) Nitrosobenzene (c) Aniline (d) p-hydroxyaniline

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SECTION IV Matrix Match Type This section contains 2 questions. Each question contains statements given in two columns which have to be matched. Statements (A), (B), (C), (D) in Column I have to be matched with statements (1, 2, 3, 4) in Column II. One statement in first column has one or more than one match with the statements in second column. The answers to these questions have to be appropriately bubbled as illustrated in the following example. If the correct matches are A 1,3, B 3, C 2,3 and D 2,4, then the correctly bubbled 4 × 4 matrix should be as follows: 1 2 3 4 A B C D

1

2

3

1

2

3

4 4

1

2

3

4

1

2

3

4

1. Column I

Column II

(A) Poling

1.

Titanium

(B) Cupellation

2.

Copper

(C)

Electro-refining

3.

Silver

(D)

Van Arkel method

4.

Zirconium

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2. Column I CH2CH2Cl (A)

Column II

CH3O–

1.

SN1

alc.KOH

2.

SN2

H2O / OH–

3.

E1

4.

E2

Cl (B) Cl

(C)

OH (D)

H+

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SECTION V Subjective or Numerical Type The answer to these questions would lie between 0 to 9999. For any answer all four bubbles must be filled, for example if you plan to answer as 16 then fill 0016 and if you plan to answer 0 then fill 0000 in the grid provided in answer sheet. In case the answer is a fraction, round it off to the nearest whole number. For example, 725.3 is rounded off to 0725. Any incomplete filling will be considered as incorrect filling. Illustration: If you want to fill 2379 as your answer then it will be filled as

1.

Depression in freezing point of 0.01 molal aqueous HCOOH solution is 0.02046. 1 molal aqueous urea solution freezes at –1.86°C. Assuming molality equal to molarity, calculate the pH of HCOOH solution.

2.

If (x/m) represents the extent of adsorption of a gas at pressure P on the surface of a solid, the graph between x log and log P is a straight line at angle 45° with m x intercept OA as shown. Calculate the value of at m a pressure of 2 atmosphere.

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x log A m 0

45° log 2 log P