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CHEMISTRY

Daily Practice Problems Target IIT JEE 2013 Class:XI(PQRS)

Marks : 25

Discussion: 03-04/08/2011

Time: 30 Min.

DPP NO. 17

Only one option is correct : Q.1 Decreasing order (first having highest & then others following it) of mass of pure NaOH in each of the aqueous solution [2] (i) 50 gm of 40% (w/w) NaOH (ii) 50 gm of 50% (w/v) NaOH [dsoln. = 1.2 gm/ml] (iii) 50 gm of 20 M NaOH [dsoln. = 1 gm/ml] (A) (i), (ii), (iii) (B) (iii), (ii), (i) (C) (ii), (iii), (i) (D) all contain same wt. of NaOH Q.2

If ratio of mole fraction of solute to solvent is unity, what would be % by wt. (concentration of solute) (M solute = molecular mass of solute, M solvent = M molecular mass of solvent) [2] M solute (A) × 100 (B) 50% (M solute  M solvent) M solute (C) 66.67 % (D) × 100 M solvent

Q.3

Arrange in increasing order of Molarity of solute in following solutions considering water as solvent. [2] (i) 224 gm/lit. KOH (ii) 11.2% w/v KOH (iii) 5m KOH (d = 0.64 gm/ml) (A) (ii) < (iii) < (i)

(B) (iii) < (ii) < (i)

(C) (iii) < (i) < (ii)

(D) (i) < (ii) < (iii)

Comprehension: Drinking is injurious of health. But for revenue purpose government has fixed some permissible value for alcohol. The permissible value for the alcohol content in the blood is 1% by mass. On analysis of blood sample of a driver of being drunk over than the permissible value, it was obtained that 60 gm sample reacted with 30 ml of 8M K2Cr2O7 (Acidic solution) Reaction : 2K2Cr2O7 + 8H2SO4 + C2H5OH  2Cr2(SO4)3 + 11H2O + 2K2SO4 + 2CO2 Assume K2SO4 reacts only with the alcohol present in blood. Q.4 Will the driver be prosecuted for drunken. [2] (A) Yes (B) No (C) May or May not (D) Can’t say data insufficient Q.5

What is the percentage of alcohol in the blood sample. (A) 9.2 % (B) 8.8 % (C) 0.8 %

[2] (D) 7.2 %

Assertion Reason: Q.6 The questions below to consist of an Assertion and the Reason. Mark appropriate option using the given directions. (A) If both Assertion and Reason are CORRECT, and Reason is the CORRECT explanation of the Assertion. (B) If both Assertion and Reason are CORRECT, but Reason is not the CORRECT explanation of the Assertion. (C) If Assertion if CORRECT but Reason is INCORRECT. (D) If Assertion is INCORRECT Reason is CORRECT. [2] Assertion : Molarity & molality for very dilute aqueous solution is approximately same Reason : For all aqueous solution total mass of solvent is approximately equal to total volume of solution.

Match the Column: Q.7 Match the column–I with column–II and column–III and show your calculations [6] Column–I Column-II Column-III (i) 400 gm/lit NaOH (X) 6.25 m NaOH (P) 10 M NaOH if if dsolution = 1.0 gm/ml if dsolution = 2 gm/ml (ii) 20% w/w NaOH (Y) 0.166 mole fraction (Q) 7142.5 ppm of NaOH if if dsolution = 1 gm/ml if dsolution = 1.3 gm/ml Subjective: Q.8 When 20 ml of pure acetic acid (density = 0.75 gm ml–1 ) is mixed with 50 gm of water (density = 1gm ml–1) at a certain temperature. Calculate the molality of acetic acid in the final solution.[2] Q.9

Calculate the minimum molarity of a H2O2 solution, which can produce at least 1 gm each of I2 & KOH, when 5 litre of H2O2 solution is added to excess KI solution. H2O2 + 2KI  I2 + 2KOH [3]

Q.10 Calculate molarity of NaOH in a solution made by mixing 2 lit. of 1.5 M NaOH, 3 lit. of 2M NaOH and 1 lit. water. [2] FROM TEACHER’S CORNER:

"THE FULL USE OF YOUR POWERS ALONG LINES OF EXCELLENCE."

DPP ANALYSIS TOOL (TA)

IIT-JEE preparation involves a continuous & rigorous analysis of your attempts of the questions. Evaluate your DPP performance using the below tool to identify your weak areas. Make it a habit to increase your chances of getting selected in IIT JEE. Analysis Key

Topics:

MC- Mole concept

Sub-Topics:

(i) Percentage Concentration Term(PCT) (ii) Molarity and Molality Term (MT) (iii) Mixed Concentration Term (MCT)

Level :

E - Easy,

Category:

(i) (ii) (iii) (iv) (v) (vi)

Q.NO. TOPIC SUB TOPIC LEVEL C ATEGORY EV ALUATION

M-Medium,

D-Difficult

(DFB): Direct formula based (FI):Factual Info Based Tricky/Googly (T) : Mistake prone question Mixed concepts (MCB) : Based on more than one concept Advanced Learning (AL) : Above JEE level, useful for understanding Theory Based (TB)

1 MC MCT

2 MC MP

3 MC MCT

4 MC PCT

5 MC PCT

6 MC MT

7 MC MCT

8 MC MT

9 MC MT

10 MC MT

E TB

E TB

E TB

E TB

E TB

E TB

M TB

E TB

M TB

E TB

CHEMISTRY

Daily Practice Problems Target IIT JEE 2013 Class:XI(PQRS)

Marks : 31

Discussion: 05-06/08/2011

Time: 35 Min.

DPP NO. 18

Only one option is correct : Q.1 The NH3 evolved from 1.40 gm sample of protein was absorbed in 45 ml of 0.4 M HNO3. The excess acid required 20 ml of 0.1 M NaOH. The % N in the sample is [2] (A) 8 (B) 16 (C) 19.42 (D) None Q.2

Methyl benzoate is prepared by the reaction between benzoic acid and methanol, according to the equation C6H5COOH + CH3OH  C6H5COOCH3 + H2O [2] Benzoic acid Methanol Methyl benzoate In an experiment 24.4 gm of benzoic acid were reacted with 70.0 mL of CH3OH. The density of CH3OH is 0.79 g mL–1. The methyl benzoate produced had a mass of 21.6 g. What was the percentage yield of product ? (A) 91.7% (B) 79.4% (C) 71.5% (D) 21.7% Paragraph for question nos. 3 to 4 1292.5 gm of aquesous solution of ‘5m’ NaCl is kept in a large bucket. The bucket is placed under a tap from which a ‘2m’ aqueous solution of NaCl is flowing. Rate of flow of solution from tap is 0.5 gm/sec.

Q.3

The total amount of solution (in gm) finally present in bucket when solution present in bucket have concentration of NaCl 4m. [3] (A) 558.5 (B) 1851 (C) 1351 (D) 1938.75

Q.4

The time (in seconds) after which the bucket will have ‘4m’ concentration of NaCl. (A) 117 (B) 2000 (C) 1117 (D) 1292.5

[3]

Q.5

If in a sample of oleum, mole fraction of SO3 is 0.5. Label the oleum sample (A) 109 % (B) 110.11 % (C) 104.5 % (D) 114.22

[2]

Assertion Reason: Q.6 Statement-1: For reaction 2A(g) + 3B(g)  4C(g) + D(g) vapour density remain constant throughout the course of reaction. Statement-2: In all gaseous chemical reaction vapour density remain constant. [2] (A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1. (B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for statement-1. (C) Statement-1 is true, statement-2 is false. (D) Statement-1 is false, statement-2 is true.

Match the column [9] Q.7 Column-I and column-II contains four entries each. Entry of column-I is to be matched with only one entry of column-II. Column I Column II (A) 5 m NaOH solution (P) 16 M (dsolution = 0.6 gm /ml). Molalrity of solution is (B) 250 ml of H2O2 solution (Q) 1M provides 64 gm O2 . Molalrity of H2O2 solution is (C) 100 ml , 1 M H2SO4 solution (R) 2.5 M (dsolution = 1.5 gm/ml) is mixed with 400 ml of water, density of final solution 1.25 gm/ml Final Molalrity of H2SO4 solution is (D) 100 ml, 6 M NaCl solution is mixed with (S) 0.227 M 100 ml of 17% AgNO3 solution (dsolution=8 gm/ml) Molalrity of Ag+ ions in final solution is Molarity Subjective of Cl¯ Q.8 For an aqueous solution having CaCl2 (5M) and MgCl2 (5m), B Molality the specific gravity of solution is 1.145. of Cl¯ A Calculate C, where C = A + B. [3] Q.9

If 200 ml of 0.1 M Na2SO4 is mixed with 100 ml of 0.2 M Na3PO4 solution. Molarity of Na+ in the final solution, if final solution has density 1.2 gm/ml.[Multiply your answer by 100] [2]

Q.10 25 ml of a solution containing HCl and H2SO4 required 10 ml of 1M NaOH solution for complete neutralization. 20 ml of the same acid mixture on being treated with excess of AgNO3 gives 0.1435 gram of AgCl. If molarity of HCl is 'x' and that of H2SO4 is 'y'. [3] Report your answer as (x + y) × 1000. FROM TEACHER’S CORNER:

"VICTORY GOES TO THE PLAYER WHO MAKES THE NEXT-TO-LAST MISTAKE."

DPP ANALYSIS TOOL IIT-JEE preparation involves a continuous & rigorous analysis of your attempts of the questions. Evaluate your DPP performance using the below tool to identify your weak areas. Make it a habit to increase your chances of getting selected in IIT JEE. Analysis Key Topics: MC- Mole concept Sub-Topics: (i) Percentage Concentration Term(PCT) (ii) Molarity and Molality Term (MT) (iii) Mixed Concentration Term (MCT) (iv) Mole Method (MOM) (v) Oleum concentration Term (OCT) Level : E - Easy, M-Medium, D-Difficult Category: (i) (DFB): Direct formula based (ii) (FI):Factual Info Based (iii) Tricky/Googly (T) : Mistake prone question (iv) Mixed concepts (MCB) : Based on more than one concept (v) Advanced Learning (AL) : Above JEE level, useful for understanding (vi) Theory Based (TB) (TA)

Q.NO. TOPIC SUB TOPIC LEVEL C ATEGORY EV ALUATION

1 MC MOM

2 MC MOM

3 MC M OM

4 MC MT

5 MC MT

6 MC OCT

7 MC MOM

8 MC MCT

9 MC MT

10 MC MT

E TB

E TB

M TB

M TB

E TB

E TB

M TB

M TB

E TB

M TB