Chemistry

7/16/2019 Chemistry

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INTRODUCTION AND CLASSIFICATION

(1) In a homogenous mixture, the diameter of the molecular particle is............meter.

(a) 10-9 m (b) 10-8 m (c) 10-9 cm (d) 10-8 cm

Ans : (a)

(2) The component with lesser proportion in solution is...........(a) solvent (b) solution (c) solute (d) None of these

Ans : (c)

(3) Which of the following is a solution?

(a) Copper (b) Zinc (c) Brass (d) Nickle

Ans : (c)

(4) Soda water is of which type solution?

(a) Solid solution (b) Liquid solution (c) Gaseous solution (d) None of these

Ans : (b)(5) What is the physical state of solute and solvent in moist air, respectively?

(a) Solid-Liquid (b) Gas-Liquid (c) Liquid-Gas (d) Solid-Gas

Ans : (c)

(6) Zn/Hg amolgum is..............solution.

(a) Solid (b) Liquid (c) Gas (d) Colloidal

Ans : (a)

(7) Which types of substances dissolve in non polar solvent?

(a) Ionic (b) Substance with -OH group

(c) Polar (d) Non polar

Ans : (d)

(8) Which is the most soluble in water?

(a) Ethanol (b) Benzene (c) Glycerol (d) All of these

Ans : (c)

\Glycerol has the

2 2CH CH CH

| | |

OH OH OH

maximum, number of -OH group.(9) Which of the following is not a proper solution?

(a) Benzene and either (b) HCl in water

(c) Water and benzene (d) Water and ethanol

Ans : (c)

(10) Most of the ionic substances are dissolved in..............

(a) water (b) alcohol (c) ether (d) benzene

Ans : (a)

(11) Pickup the correct formula of potash alum.

(a) 2 4 2 4 3 2K SO Al (SO ) 24H O (b) 2 4 2 4 2 2K SO Al (SO ) 24H O

(c) 2 4 2 4 3 2K SO Al (SO ) 12H O (d) 2 4 2 4 3 2K SO Al (SO ) 24H O

Ans : (a)

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(12) By which of the following, between solute and solvent, the solution will formed?

(a) Association (b) Dissociation

(c) Neutralization (d) Attractive interaction

Ans : (d)

(13) Dispersion of comphor in air is...........solution.

(a) solid (b) liquid (c) gaseous (d) None of these

Ans : (c)(14) Which of the following is non aqueous solvent?

(a) Benzene (b) Ether (c) CCl4 (d) All of these

Ans : (d)

(15) Which of the following is more soluble in water?

(a) Propanol (b) 1, 2 propane diol

(c) Glycerol (d) 1, 3 propane diol

Ans : (c)

3 2 2CH CH CH OH

Propanol

3 2CH CH CH OH

|OH

1, 2-Propane diol

2 2CH CH CH| | |OH OH OH

Glycerol

2 2 2CH CH CH| |OH OH

(16) ........have solid solvent and liquid solute

(a) Water of sugar (b) 2H / P d

(c) Na/Hg (d) moist air

Ans : (c)

(17) .............is the example of gaseous solution.

(a) Soda water (b) Zn/Hg (c) Comphor in air (d) salt in water

Ans : (c)

1, 3-Propane diol(18) The dissolution of gaseous solute in liquid solvent is which type process?

(a) Exothermic (b) Endothermic (c) Neutralization (d) None of these

Ans : (d)

19. In liquid CCl4 , which of the following has maximum solubility

(a) Cl2 (b) Br2 (c) I2 (d) NaCl

Ans: (b) Br2

20. Iodine is more soluble in alcohol than in carbon tetrachloride because

(a) Iodine and alcohol both are non-polar

(b) Randomness factor is greater in alcohol than in CCl4

(c) Dissolution of iodine in alcohol is exothermic whereas it is endothermic in CCl4

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(d) Dissolution of both is endothermic but heat of dissolution in alcohol is less than in CCl 4

Ans: (d) Dissolution of both is endothermic but heat of dissolution in alcohol is less

than in CCl4

(2) A solid is dissolved in water if

(a) Lattice energy is greater than hydration energy

(b) Lattice energy is less than hydration energy

(c) Lattice energy is equal to hydration energy

(d) Dissolution is exothermic

Ans: (b) Lattice energy is less than hydration energy

(3) Dissolution of a solute is an exothermic process when

(a) Hydration energy > Lattice energy (b) Hydration energy < Lattice energy(d) Solution process is

endothermic

Ans: (c) Solution process is endothermic till 34°C and exothermic there after

Hint: The ascending slope of graph indicates increasing solubility and the descending slope

indicates decreasing solubility with increase in temperature.

(4) The solubility of NaCl is least affected by increase in temperature because,

(a) It has high solubility

(b) It is an ionic compound

(c) Its lattice energy is almost equal to its hydration energy

(d) Lattice energy does not play any role

Ans: (c) Its lattice energy is almost equal to its hydration energy

(5) Which of the following will have the highest boiling point at 1 atm pressure?

(a) 0.1 M NaCl (b) 0.1 M sucrose

(c) 0.1 M BaCl2 (d) 0.1 M glucose

Ans: (c) 0.1 M BaCl2

(6) 0.01 molar solutions of glucose, phenol and potassium chloride were prepared in water. the boiling

points of

(a) Glucose solution = Phenol solution = Potassium chloride solution

(b) Potassium chloride solution > Glucose solution > Phenol solution

(c) Phenol solution > Potassium chloride solution > Glucose solution

(d) Potassium chloride solution > Phenol solution > Glucose solution

Ans: (d) Potassium chloride solution > Phenol solution > Glucose solution

(7) Which one has the highest boiling point?

(a) 0.1 N Na2SO4 (b) 0.1 N MgSO4

(c) 0.1 M Al2(SO4)3 (d) 0.1 M BaSO4

Ans: (c) 0.1 M Al2(SO4)3

(8) Which of the following solutions will have the highest boiling point?

(a) 1% glucose (b) 1% sucrose

(c) 1% NaCl (d) 1% CaCl2

Ans: (d) 1% CaCl2

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(9) Which solution will have the highest boiling point?

(a) 1% solution of glucose in water (b) 1% solution of sodium chloride in water

(c) 1% solution of zinc sulphate in water (d) 1% solution of urea in water

Ans: (b) 1% solution of sodium chloride in water

(10) Which has the minimum freezing point?

(a) One molal NaCl solution (b) One molal KCl solution

(c) One molal CaCl2solution (d) One molal urea solutionAns: (c) One molal CaCl2solution

(11) The freezing point of a dilute solution of acetamide in glacial acetic acid is 298 K. This is the

value when crystals of

(a) Acetamide first appears (b) Acetic acid first appears

(c) Both appear together (d) Ice first appears

Ans: (b) Acetic acid first appears

(12) The melting points of most of the solid substances increase with an increase of pressureacting on them. However, ice melts at temperature lower than its usual melting point, when the

pressure increases. This is because

(a) Ice is less denser than water (b) Pressure generates heat

(c) The bonds break under pressure (d) Ice is not a true solid

Ans: (b) pressure generates heat

(13) In cold countries, ethylene glycol is added to water in the radiations of cars during winter.

This results in

(a) Lowering of F.P. (b) Reducing the viscosity(c) Reducing the specific heat (d) Making water a better conductor of electricity

Ans: (a) Lowering F.P

(14) What would happen if a thin slice of sugar beet is placed in a concentrated solution of NaCl

(a) Sugar beet will lose water from its cells

(b) Sugar beet will absorb water from solution

(c) Sugar beet will neither absorb nor lose water

(d) Sugar beet will dissolve in solution

Ans: (a) Sugar beet will lose water from its cells

(15) Azeotropic mixture of HCl and water has

(a) 84% HCl (b) 22.2% HCl

(c) 63% HCl (d) 20.2% HCl

Ans: (d) 20.2% HCl

(16) A maxima or minima obtained in the temperature, composition curve of a mixture of two

liquids indicates

(a) An azeotropic mixture (b) An eutectic formation

(c) That the liquids are immiscible with one another

(d) That the liquids are partially miscible at the maximum or minimum

Ans: (a) An azeotropic mixture.

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(17) What would happen if a thin slice of sugar beet is placed in a concentrated solution of NaCl

(a) Sugar beet will lose water from its cells

(b) Sugar beet will absorb water from solution

(c) Sugar bee

(c) Hydration energy = Lattice energy (d) None of these

Ans: (a) Hydration energy > Lattice energy

Hint: Lattice energy is less than hydration energy

(18) Which of the following condition is not satisfied by ideal solution?

(a) ΔH = 0 (b) ΔV = 0

(c) obeys raoult’s law (d)ΔG = 0

Ans: (d)

(19) For a solution of acetone in CS2 the value of ΔS is

(a) > 0 (b) < 0 (c) = 1 (d) = 0

Ans: (a)

(20) Which of the following condition is not satisfied by an ideal solution?

(a) ΔH = 0 (b) ΔS = 0 (c) ΔV = 0 (d) raoult’s law is obeyed

ANS (b)

(21) When a saturated solution of sodium chloride is heated it becomes,

(a) Unsaturated (b) remains saturated

(c) Supersaturated (d) attains equilibrium conditions

ANS (a)

(22) Arrange the following aqueous solution in order of their increasing boiling points

(i) 0.001 M NaCl (ii) 0.001 M urea

(iii) 0.001 M MgCl2 (iv) 0.01 M NaCl

(a) II < I < III <IV (b) I < II < IV < III

(c) II < I = III < IV (d) IV < III < I < II

(23) Arrange the following aqueous solution in order of their increasing boiling points

(i) 0.001 M NaCl (ii) 0.001 M urea

(iii) 0.001 M MgCl2 (iv) 0.01 M NaCl

(a) II < I < III <IV (b) I < II < IV < III

(c) II < I = III < IV (d) IV < III < I < II

ANS (a)

(24) After dissolving outer hard shell of an egg in dil. HCl, it is placed in concentration solution of

sodium chloride. What will happen to egg?(a) It cooked gradually with salty taste

(b) It will swell

(c) It will shrink

(d) It will form homogenous solution due to diffusion

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ANS (c)

(25) In which of the following solution ion-dipole are major interaction between solute and

solvent?

(a) Acetone in ethanol

(b) Iodine in chloroform

(c) Bromine in carbon disulphide

(d) Potassium bromide in waterANS (d)

(26) The molecular mass of acetic acid dissolved in water is 60 and when dissolved in benzene it

is 120. This difference in behaviour of CH3COOH is because

(a) Water prevents association of acetic acid

(b) Acetic acid does not fully dissolve in water

(c) Acetic acid fully dissolves in benzene

(d) Acetic acid does not ionize in benzeneAns: (b) Acetic acid does not fully dissolve in water

Hint: Acetic acid forms a dimer in benzene, because it is a non polar solvent.

(27) Acetic acid dissolved in benzene shows a molecular weight of

(a) 60 (b) 120

(c) 180 (d) 240Ans: (b) 120

Hint: Due to dimerization of acetic acid in non polar solvent benzene, its molecular weight is

doubled.

(28) The Solubility of a gas in water depends on

(a) Nature of the gas (b) Temperature

(c) Pressure of the gas (d) All of the above

Ans: (d) All of the above.

(29) All form ideal solution except

(a) C6H6 and C6H5CH3 (b) C2H5Br and C2H5I

(c) C6H5Cl and C6H5Br (d) C2H5I and C2H5OH

Ans: (d) C2H5I and C2H5OH

Hint: As both are polar molecules, they will interact, hence non-ideal

(30) Liquids A and B form an ideal solution

(a) The enthalpy of mixing is zero

(b) The entropy of mixing is zero

(c) The free energy of mixing is zero

(d) The free energy as well as the entropy of mixing are each zero

Ans: (a) The enthalpy of mixing is zero

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In mixture A and B components show negative deviation as

(a) ∆Vmix>0 (b) ∆Hmix<0

(c) A-B interactions is weaker than A-A and B-B interaction

(d) A-B interactions is strong than A- A and B -B interaction

Ans: (b) ∆Hmix<0

(31) The phenomenon in which cells are shrinked down if placed in hypertonic solution is called

(a) Plasmolysis (b) Haemolysis

(c) Endosmosis (d) None of these

Ans: (a) Plasmolysis.

(32) Assertion: At low concentration benzene and toluene forms ideal solution.

Reason: Components with structural similarity forms ideal solution in general

(a) Both assertion and reason are correct, and reason is the correct explanation of the assertion

(b) Both assertion and reason are correct, but reason is not correct explanation of the assertion. \

(c) Assertion is correct, but reason is Incorrect.(d) Assertion is Incorrect, but reason is correct.

Ans: (a) Both assertion and reason are correct, and reason is the correct explanation of the

assertion

(33) Assertion: A great care taken in intra venous injections to have comparable of

concentration of solutions to be injected to that of blood plasma.

Reason: By the change of concentration the red blood cells either will swell or shrink.


(b) Both assertion and reason are correct, but reason is not correct explanation of the assertion.(c) Assertion is correct, but reason is Incorrect.

(d) Assertion is Incorrect, but reason is correct.


assertion

(11) Which is soluble and which is insoluble in water respectively?

(a) Ethanol, benzene (b) Benzene, ethanol

(c) Benzene, aniline (d) Ethanol, methanol

Ans : (a)

28) The solubility of H2S and NH3 are less in...........and more in..................

(a) benzene, water (b) water, ethanol (c) water, methanol (d) ethanol, water

Ans : (d)

UNITS OF CONCENTRATION & COLLIGATIVE PROPERTIES

(1) Calculate the weight of solution prepared by 0.1 gram NaOH in 2%w/w concentration

solution.

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(a) 2 gram (b) 5 gram (c) 10 gram (d) 50 gram

Ans : (b)

100 weight of solute% w / w

weight of solution

\ weight of solution

100 0.15

2

gram

(49) What is the formality of the solution prepared by dissolving 50 gram.4 4 2 4 2

FeSO (NH ) SO 6H O ?

(a) 0.2F (b) 0.0255F (c) 2F (d) 0.1F

Ans : (b)

(49) What is the formality of the solution prepared by dissolving 50 gram. 4 4 2 4 2FeSO (NH ) SO 6H O ?

(a) 0.2F (b) 0.0255F (c) 2F (d) 0.1F

Ans : (b)

(49) What is the formality of the solution prepared by dissolving 50 gram. 4 4 2 4 2FeSO (NH ) SO 6H O ?

(a) 0.2F (b) 0.0255F (c) 2F (d) 0.1F

Ans : (b)

(45) What will be % W/W of 2 m NaOH solution at 298K temperature?

(a) 74% (b) 7.4% (c) 0.74% (d) 0.074%

Ans : (b)

O

100 Wm , W 80 gram

M W

100 weight 100 80%W / W 7.41%

Solution wight 1080

(42) Calculate % W/v containing 400 gram urea dissolve in 2 lit. solution.

(a) 10% (b) 20% (c) 30% (d) 5%

Ans : (b)

100 substance%W/V

volume of solution

100 40020%

2000

(27) Calculate the ppm by wt/volume when 2 10-6 kilogram sulphur dissolve in 2 lit. solution.

(a) 1 (b) 10 (c) 102

(d) 103

Ans : (a)

2 lit. solution 32 10 ml.

Mass of sulphur 6 32 10 Kg. 2 10 gram

PPM by 6SoluteW / V 10

Solution

36

3

2 1010 1

2 10

(25) How much sugar is required to prepare 2 lit 5% W/V sugar solution?

(a) 100 (b) 500 (c) 750 (d) 1000

Ans : (a)

(26) What will be the %W/V when 200gram Urea dissolve in 5 lit Solution?

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(a) 2% (b) 4% (c) 8% (d) 10%

Ans : (b)

100 200%W / V 4%

5000

(24) How much ml. kerosene required to prepare 5 liter 15%V/V kerosene solution in petrol?

(a) 500 (b) 250 (c) 750 (d) 1000

Ans : (c)

100 volume of kerosene%V/V

volume of solution

100 volume of kerosene15

500

Volume15 5000

750100

ml

(21) In 1 kilogram sample of water, CaSO4 is found up to 0.01 gram. For Ca+2, how many ppm present in

sample?

(a) 1 ppm (b) 10 ppm (c) 210 ppm (d) 310 ppm

Ans : (b)

(22) What is the formality of solution prepared by dissolving 948 gram potash alum in 5 liter solution?

(a) 0.2 F (b) 0.3 F (c) 0.4 F (d) 0.04 F

Ans : (c)

(23) Calculate %V/V when 200 ml. ethanol dissolve in 2 liter aqueous solution of ethanol.

(a) 10% (b) 20% (c) 30% (d) 40%

Ans : (a)

(16) What is the molecular weight and formula weight ratio of potash alum?

(a) 1 : 2 (b) 2 : 1 (c) 1 : 1 (d) 1 : 3

Ans : (b)

For potash alum,

Molecular weight : Formula weight

948 : 474

2 : 1

(17) ........have solid solvent and liquid solute.

(a) Water of sugar (b) 2H /Pd


Ans : (c)



Ans : (c)

(19) What is the formula weight of potash alum?

(a) 948 gram/f.weight (b) 474 gram/f.weight

(c) 747 gram/f.weight (d) 774 gram/f.weight

Ans : (b)

(20) The empirical formula of potash alum is....

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(a) 4 2 2K Al(SO ) 12H O (b) 2 4 2 2

K Al(SO ) 12H O

(c) 2 4 2 2K Al (SO ) 12H O (d) 4 2 2

K Al(SO ) 24H O

Ans : (a)

(21) Formality unit is used in which scientific field?

(a) Pharmacy (b) Medical

(c) Agriculture (d) (a) and (b) both

Ans : (d)

(22) The solution prepared by dissolving one gram formula mass of the substance in one litre is

called..........solution.

(a) 1 normal (b) 1 molar (c) 1 molal (d) 1 formal

Ans : (d)

(23) The amount of pollution in air is shown by............unit.

(a) formality (b) % W/V (c) % V/V (d) ppm

Ans : (d)

(24) The amount of O2 gas dissolved in sea water is given by................unit.

(a) normality (b) ppm (c) %W/V (d) formality

Ans : (b)

(25) Which of the following is temperature independent form?

(a) Molality (b) Molarity (c) Normality (d) Formality

Ans : (a)

(26) ...........unit is changed with change in temperature.

(a) % by volume (b) molality (c) mole fraction (d) w/w %

Ans : (a)

(27) Which unit is used to show very less amount of solute in the solution?

(a) F (b) N (c) M (d) ppm Ans : (d)

1. Molarity of 4% NaOH solution is

(a) 0.1 M (b) 0.5 M

(c) 0.01 M (d) 1.0 M

Ans: (d) 1.0 M

Hint: 4% means 4 g in 100 ml,

Hence, M =

2. If 5.85 g of NaCl (Molecular weight 58.5) is dissolved in H2O and solution made upto 0.5 litre. The

molarity of this solution will be

(a) 0.1 (b) 0.2

(c) 1 (d) 0.4

Ans: (b) 0.2

Hint: M =

3. Molarity is expressed as

(a) Gram/litre (b) Litre/mole

(c) Moles/litre (d) Moles/1000 gm

Ans: (c) Moles/litre

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4. The molarity of a solution prepared by adding 7.1 of Na2SO4 (formula weight 142 amu) to enough

water to make 100 ml volume is

(a) 2.0 M (b) 1.0 M

(c) 0.5 M (d) 0.05 M

Ans: (c) 0.5 M

Hint: M =

5. The molarity of 0.006 mole of NaCl in 100ml solution is

(a) 0.6 (b) 0.06

(c) 0.006 (d) None

Ans: (b) 0.06

Hint: M =

6. Molarity of a solution prepared by dissolving 75.5 g of pure KOH in 540 ml solution is

(a) 3.05 M (b) 1.35 M(c) 2.50 M (d) 4.50 M

Ans: (c) 2.50 M

Hint: M =

7. Increasing the temperature of an aqueous solution will cause

(a) Decrease in molality (b) Decrease in molarilty

(c) Decrease in mole fraction (d) Decrease in % W/W

8. In 5.85 g of NaCl one kg of water is added to prepare a solution. What is the concentration of NaCl

in this solution (mol. wt. of NaCl = 58.5 )(a) 0.1 Normal (b) 0.1 Molal

(c) 0.1 Molar (d) 0.1 Formal

Ans: (b) 0.1 molal

Hint: 5.85 g NaCl is 0.1 mole of NaCl. So 0.1 mol NaCl is dissolved in 1 Kg H2O hence it is 0.1

molal

9. The number of moles of solute per kg of a solvent is called its

(a) Molarity (b) Normality

(c) Molar fraction (d) MolalityAns: (d) Molality

Hint: molality = mol/Kg

10. Molecular weight of glucose is 180. A solution of glucose which contains 18 gms per litre is

(a) 2 molar (b) 1 molar

(c) 0.1 molar (d) 18 molar

Ans: (c) 0.1 molar

Hint: M =

11. Which is the following modes of expressing concentration is independent of temperature

(a) Molarity (b) Molality

(c) Formality (d) Normality

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Ans: (b) Molality

Hint: Molality, % w/w and mole fraction are independent of temperature as they do not depend

upon volume of solution.

12. A molal solution is one that contains one mole of a solute in

(a) 1000 gm of the solvent (b) One litre of the solvent

(c) One litre of the solution (d) 22.4 litres of the solution

Ans: (a) 1000 gm of the solvent

13. If 18 g of glucose (C6H12O6)is present in 1000 g of an aqueous solution of glucose, it is said to be

(a) 1 molal (b) 1.1 molal

(c) 0.5 molal (d) 0.1 molal

Ans: (d) 0.1 molal

Hint: m =

14. The weight of H2C2O4.2H2O required to prepare 500ml of 0.2N solution is

(a) 126 g (b) 12.6g

(c) 63g (d) 6.3g

Ans: (d) 6.3g

Hint: N =

∴ 0.2 =

∴ W = 6.3

15. The normality of 10% (weight / volume) acetic acid is

(a) 1 N (b) 10 N(c) 1.7 N (d) 0.83 N

Ans: (c) 1.7 N

Hint: 10% w/v means 10 g acetic acid dissolved in 100 ml of solution

Now, N =

16. On dissolving 1 mole of each of the following acids in 1 litre water, the acid does not give a solution

of strength 1N is

(a) HCl (b) Per chloric acid

(c) HNO3 (d) Phosphoric acid

Ans: (d) Phosphoric acid

Hint: Phosphoric acid H3PO4 is a tribasic acid, hence its equivalent mass will be 1/3 of

molecular mass. So, N = M x 3.

17. The normality of solution of NaOH ;100 ml of which contains 4 g of NaOH is

(a) 0.1 (b) 40

(c) 1.0 (d) 4.0

Ans: (c) 1.0

Hint: N =

18. Unit of mole fraction are

(a) moles / L (b) moles / L2

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(c) moles litre (d) Dimensionless

Ans: (d) Dimensionless

19. If we take 44 g of CO2 and 14 g of N2 what will be mole fraction of CO2 in the mixture

(a) 1/5 (b) 1/3

(c) 2/3 (d) ¼

Ans: (c) 2/3

Hint: Mole of CO2 = W/MM = 44 / 44 = 1 moleMole of N2 = W/MM = 14 / 28 = 0.5 mole

Mole fraction of CO2 =

20. In solution of 7.8 g of benzene (C6H6)and 46 g of toluene (C6H5CH3), the mole fraction of benzene in

this solution is

(a) 1/6 (b) 1/5

(c) ½ (d) 1/3

Ans: (a) 1/6

Hint: Mole of benzene = 7.8 / 78 = 0.1 mol

Mole of toluene = 46/92 = 0.5 mol

Mole fraction of benzene =

21. If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is

(a) 0.1 (b) 0.2

(c) 0.01 (d) 0.0196

Ans: (d) 0.0196

Hint: Mole of NaCl = 5.85/58.5 = 0.1 molMole of Water = 90/18 = 5 mol


22. The number of moles of a solute in its solution is 20 and total number of moles are 80. The mole

fraction of solute is

(a) 2.5 (b) 0.25

(c) 1 (d) 0.75

Ans: (b) 0.25

Hint: Mole fraction =

23. What volume of 0.8 M solution contains 0.1 mole of the solute

(a) 100ml (b) 125ml

(c) 500ml (d) 62.5ml

Ans: (b) 125ml

Hint: M =

∴ V =

24. 10 grams of a solute is dissolved in 90 grams of a solvent. Its mass percent in solution is

(a) 0.01 (b) 11.1

(c) 10 (d) 9

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Ans: (c) 10

Hint: % w/w =

25. A aqueous solution of glucose is 10% in strength. The volume in which one gram mole of is

dissolved will be

(a) 18 litre (b) 9 litre

(c) 0.9 litre (d) 1.8 litre

Ans: (d) 1.8 litre

Hint: 1 g mole of glucose is 180 g/mol

∴ % w/v =

∴ 10 =

∴ V = 1800 ml = 1.8 L

26. In solution of 7.8 g of benzene (C6H6)and 46 g of toluene (C6H5CH3), the mole fraction of benzene in

this solution is

(a) 1/6 (b) 1/5

(c) ½ (d) 1/3

Ans: (a) 1/6

Hint: Mole of benzene = 7.8 / 78 = 0.1 mol

Mole of toluene = 46/92 = 0.5 mol


27. If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is

(a) 0.1 (b) 0.2

(c) 0.01 (d) 0.0196

Ans: (d) 0.0196

Hint: Mole of NaCl = 5.85/58.5 = 0.1 mol

Mole of Water = 90/18 = 5 mol


28. The number of moles of a solute in its solution is 20 and total number of moles are 80. The mole

fraction of solute is

(a) 2.5 (b) 0.25

(c) 1 (d) 0.75Ans: (b) 0.25

Hint: Mole fraction =

29. What volume of 0.8 M solution contains 0.1 mole of the solute

(a) 100ml (b) 125ml

(c) 500ml (d) 62.5ml

Ans: (b) 125ml

Hint: M =

∴ V =

30. 10 grams of a solute is dissolved in 90 grams of a solvent. Its mass percent in solution is

(a) 0.01 (b) 11.1

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(c) 10 (d) 9

Ans: (c) 10

Hint: % w/w =

31. A aqueous solution of glucose is 10% in strength. The volume in which one gram mole of is

dissolved will be

(a) 18 litre (b) 9 litre

(c) 0.9 litre (d) 1.8 litre

Ans: (d) 1.8 litre

Hint: 1 g mole of glucose is 180 g/mol

∴ % w/v =

∴ 10 =

∴ V = 1800 ml = 1.8 L

32. 1 Molar solution contains(a) 1000 g of solute (b) 1000 g of solvent

(c) 1 litre of solvent (d) 1 litre of solution

Ans: (d) 1 litre of solution.

Hint: Molarity = Mole/Litre

33. With increase of temperature, which of these changes

(a) Molality (b) Weight fraction of solute

(c) Fraction of solute present in water (d) Mole fraction

Ans: (c) Fraction of solute present in water.

Hint: Molality, Weight fraction and mole fraction does not depend upon temperature.

34. 2.0 molar solution is obtained, when 0.5 mole solute is dissolved in

(a) 250 ml solvent (b) 250 g solvent

(c) 250 ml solution (d) 1000 ml solvent

Ans: (c) 250 ml solution.

Hint: M =

Volume = = 0.25 L =250 ml

35. What is the molality of a solution which contains 18 g of glucose (C6H12O6)in 250 g of water?

(a) 4.0m (b) 0.4m

(c) 4.2m (d) 0.8m

Ans: (b) 0.4 m

Hint: m =

= 0.4 m

36. When a solute is present in trace quantities the following expression is used

(a) Gram per million (b) Milligram percentage

(c) Microgaram percentage (d) Parts per million

Ans: (d) parts per million

37. 3.0 molal NaOH solution has density of 1.110 g / ml . The molarity of this solution is

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(a) 3.0504 (b) 3.64

(c) 3.05 (d) 2.9732

Ans: (d) 2.9732

Hint:

38. 25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid

gave a litre value of 35 ml. The molarity of barium hydroxide solution was

(a) 0.07 (b) 0.14

(c) 0.28 (d) 0.35

Ans: (a) 0.07

Hint: M1V1=M2V2

39. 2.5 litre of 1M NaOH solution are mixed with another 3 litre of 0.5 M NaOH solution. Then the

molarity of the resulting solution is

(a) 0.80 M (b) 1.0 M

(c) 0.73 M (d) 0.50 M

Ans: (c) 0.73 M

Hint: MV = M1V1 + M2V2

40. The normality of 10 litre volume hydrogen peroxide is

(a) 0.176 (b) 3.52

(c) 1.78 (d) 0.88

Ans: (c) 1.78

41. What will be the normality of a solution containing 4.9 g H3PO4 dissolved in 500 ml water

(a) 0.3 (b) 1.0

(c) 3.0 (d) 0.1

Ans: (a) 0.3

Hint: N =

42. The molality of a sulphuric acid solution in which the mole fraction of water is 0.85 is

(a) 9.80 (b) 10.50

(c) 10.58 (d) 11.25

Ans: (a) 9.80

Hint: m =

43. Which one of the statements given below concerning properties of solutions, describes a colligative

effect?

(a) Boiling point of pure water decreases by the addition of ethanol

(b) Vapour pressure of pure water decreases by the addition of nitric acid

(c) Vapour pressure of pure benzene decreases by the addition of naphthalene

(d) Boiling point of pure benzene increases by the addition of toluene

Ans: (b) Vapour pressure of pure water decreases by the addition of nitric acid

44. The osmotic pressure of which solution is maximum (consider that deci-molar solution of each 90%

dissociated)

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(a) Aluminium sulphate (b) Barium chloride

(c) Sodium sulphate (d) A mixture of equal volumes of (b) and (c)

Ans: (a) Aluminium sulphate

45. Which of the following colligative property is associated with the concentration term? molarity?

(a) Osmotic pressure (b) depression in F. P.

(c) Elevation of B. P. (d) Relative lowering of V.P.

Ans: (a) Osmotic pressure46. A solution is formed by dissolving “X” in alcohol. The V% of such alcoholic solution is 20. If the

volume of the solution is 250ml, calculate the volumes of alcohol and solute “X”

(a) 50 ml (b) 200 ml

(c) 250 ml (d) 500ml

Ans: (b) 200 ml

Hint: % V =

20 =

x 100

v = 50 ml

V = 250 -50 = 250 ml

47. A solution of ethanol in water is 10% by volume. If the solution and pure ethanol have densities of

0.9866 g/cc and 0.785 g/cc respectively, find the per cent by weight

(a) 7.59 % (b) 7.95 %

(c) 9.75% (d) 9.57%

Ans: (b) 7.95%

Hint: Volume of ethanol = 10 ml; vol. of solution = 100 ml

Weight of ethanol = Volume × Density = 10 × 0.785 = 7.85 g

Weight of solution = 100 × 0.9866 = 98.66 g

Weight percent = 7.85 / 98.66

= 0.0795 x 100

= 7.95 %

48. 2.12 grams of sodium carbonate Na2CO3 is present in 250 ml of its solution. Calculate the molarity

of the solution. (Molecular weight of Na2CO3 is 106).

(a) 0.04M (b) 0.06M

(c) 0.08M (d) 0.1M

Ans: (c) 0.08M

Hint: Molarity =

W = 2.12 g

Gm. mol. wt = 106

V = 250 ml. = 250/1000 = 0.25 lit

Molarity = 0.08M

49. The ratio of the value of any colligative property for KCl solution to that for sugar is nearly _______

times .

(a) 1 (b) 0.5

(c) 2 (d) 2.5

Ans: (c) 2

Hint:

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50. Which of the following concentration factor is affected by change in temperature?

(a) Molarity (b) Molality

(c) Mol fraction (d) Weight fraction

Ans: (a) Molarity

51. Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M

first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture?

(a) 1.50 M (b) 1.20 M

(c) 2.70 M (d) 1.344 M

Ans: (d) 1.344 M

Hint: MV = M1V1+ M2V2

52. Density of a 2.05 M solution of acetic acid in water is 1.02 g/mL. The molality of the solution is -

(a) 3.28 mol kg-1 (b) 2.28 mol kg-1

(c) 0.44 mol kg-1 (d) 1.14 mol kg-1

Ans: (b) 2.28 mol kg-1

Hint:

53. The molality of a urea solution in which 0.0100g of urea, [(NH2)2CO] is added to 0.3000 dm3 of water at STP is :-

(a) 0.555 m (b) 5.55 × 10-4 m

(c) 33.3 m (d) 3.33 × 10-2 m

Ans: (b) 5.55 × 10-4 m

54. The mole fraction of the solute in one molal aqueous solution is:

(a) 0.027 (b) 0.036

(c) 0.018 (d) 0.009

Ans: (c) 0.018

Hint: 1 molal = 1 mole/KgNow, 1 Kg water = 1000/18 = 55.55 mol

hence, mole fraction =

55. Concentrated aqueous sulphuric acid is 98% H2SO4 by mass and has a density of1.80 g.mL-1.

Volume of acid required to make 1 litre of 0.1 M H2SO4 solution is:

(a) 5.55 mL (b) 11.10 mL

(c) 16.65 mL (d) 22.20 mL

Ans: (a) 5.55 mL(16) What is the molecular weight and formula weight ratio of potash alum?

(a) 1 : 2 (b) 2 : 1 (c) 1 : 1 (d) 1 : 3

Ans : (b)

For potash alum,

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Molecular weight : Formula weight

948 : 474

2 : 1

(17) ........have solid solvent and liquid solute.

(a) Water of sugar (b) 2H /Pd


Ans : (c)



Ans : (c)

(19) What is the formula weight of potash alum?

(a) 948 gram/f.weight (b) 474 gram/f.weight

(c) 747 gram/f.weight (d) 774 gram/f.weight

Ans : (b)

(20) The empirical formula of potash alum is....

(a) 4 2 2K Al(SO ) 12H O (b) 2 4 2 2

K Al(SO ) 12H O

(c) 2 4 2 2K Al (SO ) 12H O (d) 4 2 2K Al(SO ) 24H O

Ans : (a)

(21) Formality unit is used in which scientific field?

(a) Pharmacy (b) Medical

(c) Agriculture (d) (a) and (b) both

Ans : (d)

(22) The solution prepared by dissolving one gram formula mass of the substance in one litre is

called..........solution.

(a) 1 normal (b) 1 molar (c) 1 molal (d) 1 formal

Ans : (d)

(23) The amount of pollution in air is shown by............unit.

(a) formality (b) % W/V (c) % V/V (d) ppm

Ans : (d)

(24) The amount of O2 gas dissolved in sea water is given by................unit.

(a) normality (b) ppm (c) %W/V (d) formality

Ans : (b)

(25) Which of the following is temperature independent form?

(a) Molality (b) Molarity (c) Normality (d) Formality

Ans : (a)

(26) ...........unit is changed with change in temperature.

(a) % by volume (b) molality (c) mole fraction (d) w/w %

Ans : (a)

(27) Which unit is used to show very less amount of solute in the solution?

(a) F (b) N (c) M (d) ppm

Ans : (d)

32) 1 ppm = .............mass of solute in 1 liter solution.

(a) 10-3 gram (b) 10-4 gram (c) 10-6 gram (d) 10-2 gram

Ans : (a)

(48) 0.1 mili mole = ............mole

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(a) 10-6 (b) 10-4 (c) 10-3 (d) 10-2

Ans : (b)

(114) What is the % weight of 6 12 6C H O ,when 10 gram 6 12 6C H O is dissolved in 150 gram water.

(a) 5% (b) 6.25% (c) 62.5% (d) 15%

Ans : (b)

10% weight 100

10 150

6.25%

(116) What is the formality of solution prepared by 4.78 gram potash alum in 2 litre solution?

(a) 0.05 (b) 0.005 (c) 5.0 (d) 0.5

Ans : (b)

m

1000 wtF

Fwt vol

1000 4.78

474 2000

0.005F

(9)230 ppm Ca ............

(a) 30 milligram/lit (b) 0.3 gram/ml. (c) 0.03 gram/lit (d) None

Ans : (a)

(10) How much NaOH dissolve to prepare 0.5 M NaOH 2 litre Solution?

(a) 4 gram (b) 0.4 gram (c) 40 gram (d) 0.04 gram

Ans : (c)

(1) Calculate the weight of solution prepared by 0.1 gram NaOH in 2%w/w concentration solution.


Ans :(b)

100 weight of solute% w / w

weight of solution

\ weight of solution100 0.1

52

gram

(2) How much NaOH required to prepare 100 ml. 0.2 N NaOH solution?

(a) 0.8 gram (b) 8 gram (c) 0.08 gram (d) 4 gram

Ans : (a)

1000 w N M.Weight Volume

1000 w

40 100

1000 w0.2

40 100

0.2 40 100W 0.8

1000

(3) How much water should be added to 2 44N H SO , to convert into 2 42M H SO solution?

(a) 100 ml. (b) 10 ml.

(c) 2 lit. (d) No need to add water

Ans : (d)

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\ N n M 4 2 2

HENRY’S LAW & RAOULT’S LAW

(30) What is the nature of graph of mole fraction of gaseous solute and its partial pressure?

(a) Straight line (b) Parabola (c) Zizag line (d) None of these

Ans : (a)

(31) What is the correct formula of K H?

(a) HK p / X (b) KH p X (c) H

K X / p (d) 2KH p X

Ans : (a)

(34) If liquids A and B form an ideal solution -

(a) The free energy of mixing is zero

(b) The free energy as well as the entropy of mixing are each zero

(c) The enthalpy of mixing is zero

(d) The entropy of mixing is zero

Ans: (c) The enthalpy of mixing is zero

(33) The solubility of gaseous solute............with increase in KH.

(a) increase (b) remain same (c) decrease (d) not given

Ans : (c)

(34) Which of the following do not follow the Henry's law?

(a) H2 (b) Ne (c) N2 (d) NH3

Ans : (d)

NH3 is reacting with water.

(35) Presently which content is used by sea divers?

(a) 11.7% He, 56% N2, 23.1% O2 (b) 11.7% He, 56% N2, 32.1% O2

(c) 11.7% N2, 56.2% O2, 32.1% He (d) 11.7% He, 56.2% N2, 32% O2

Ans : (a)

(36) The solubility of CO2 gas in cold drinks is done by which law?

(a) Raoult's (b) Boyl's (c) Henry's (d) Charle's

Ans : (c)

(37) Which is the use of Henry's law?

(a) In preparation of cold drinks (b) In biochemical processes

(c) In the industry (d) All of these

Ans : (d)

(38) The dissolution of gaseous solute in liquid solvent is which type process?

(a) Exothermic (b) Endothermic (c) Neutralization (d) None of these

Ans : (d)

(39) Which of the following statement is wrong?

(a) KH increase with increase in temperature

(b) With increase in temperature, the solubility of gaseous solute in liquid decrease.

(c) KH remains constant with change in temperature.

(d) p X

Ans : (c)

(46) Solubility of solute depends on which of the following?

(a) Nature of solvent (b) Temperature (c) Pressure (d) All of these

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Ans : (d)

(47) Which are the affecting factors on the vapour pressure?

(a) The nature of liquid (b) Temperature

(c) (a) and (b) both (d) None of these

Ans : (c)

(49) The vapour pressure of solvent of liquid solution is directly proportional to which of the following?

(a) Mole fraction of solute (b) Molality of solvent

(c) Mole fraction of solvent (d) Mole fraction of solution

Ans : (c)

(50) Raoult's law is not applicable to which solution?

(a) Very dilute solution (b) Ideal solution

(c) Solution with volatile solute (d) Solution with non volatile solute

Ans : (c)

(51) The vapour pressure of solution is............than that of pure solvent.

(a) less (b) more (c) equall (d) None of these

Ans : (a)

(52) The correct formula for Raoult's law is...

(a)0

0

p p n

p n N

(b)0

0

p p n

p n N

(c)0

0

p p N

p n N

(d)0

0

p p N

p n N

Ans : (b)

(53) According to Raoult's law, for which system of solution the vapour pressure of both i.e. solute and solvent

will be proportional to their mole fraction?

(a) Both are volatile

(b) Solute is volatile, solvent is non volatile

(c) Both are nonvoltile

Solute is nonvolatile, solvent is volatile

Ans : (a)

(54) At how much temperature, there is a vapour on the surface of volatile liquid kept in closed container?

(a) 30º C (b) 100º C (c) 273º C (d) All of these

Ans : (d)

(55) Which formula is used to calculate the molecular weight of solute in very dilute solution?

(a)0

1 2

0 1 2

w M p p

p m w

(b)0

2 1

0 2 1

w M p p

p M w

(c)0

1 2

0

1 2

w M p p

p M w

(d)

0

2 1

0

2 1

w M p p

p M w

Ans : (b)

(56) Solubility of gas follows which law?

(a) Henry's (b) Raoult's (c) Dalton's (d) Charle's

Ans : (a)

(57) Vapour pressure of solution follows which law?

(a) Henry's (b) Charles (c) Boyle's (d) Raoult's

(59) When solute and solvent both are volatile, the vapour pressure of solution is directly proportional to mole

fraction of which?

(a) Solute (b) Solvent (c) Solute and solvent (d) None

Ans : (c)

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(60) When gaseous solute dissolve in liquid solvent, the solubility of solute is given by which formula?

(a) H A p K X (b) 0

A A p p H (c) 0

H AK p X (d) H A p K / X

Ans : (a)

(61) When gaseous solute dissolve in liquid solvent, its vapour pressure is given by which formula?

(a) 0

A AP P A (b) HP K A (c) 0

A APA P / X (d) H AP K / X

Ans : (a)

(62) For the formation of ideal solution, what is the value of

H?(a) Positive (b) Negative (c) Zero (d) None of these

Ans : (c)

(63) When liquid solute and liquid solvent mix to give ideal solution, what will be change in volume (V)?

(a) Zero (b) Positive (c) Negative (d) None of these

Ans : (a)

(64) The solutions which obey the Raoult's law over the entire range of concentration is called which solution?

(a) Non ideal (b) Ideal (c) True solution (d) None of these

Ans : (b)

(65) The solution which do not obey the Raoult's law over the entire range of concentration is called which

solution?

(a) Ideal (b) Non Ideal

(c) True Solution (d) (b) and (c) both

Ans : (d)

(66) Which is correct for non ideal solution?

(a) H 0, V 0 (b) H 0, V 0

(c) H 0, V 0 (d) H 0, V 0

Ans : (a)

(67) Which of the following is a non ideal solution?

(a) Bromo ethane + chloro ethane (b) Benzene + Toluene

(c) Haxane + Heptane (d) Chloro ethane

Ans : (d)

(68) Which of the following is not a non ideal solution?

2HCl H O (b) 2 3H O HNO

(c) Phenol + Aniline (d) 6 5 6 5C H Cl C H Br

Ans : (d)

(69) Which is correct for the ideal solution?

(a) H = 0, V = 0 (b) ΔH 0, ΔV 0

(c) ΔH 0, ΔV 0 (d) ΔH 0, ΔV 0

Ans : (c)

) Which one is correct for the ideal solution having A and B component?

(a)0

AP X P (b) A BP X X

(c) A BP P P (d)

0 0

A A B BP X P X P

Ans : (d)(109) The vapour pressure of solution is directly proportional to mole fraction of which of the following?

(a) Solvent (b) Solute (c) Solution (d) All of these

Ans : (b)

(110) The vapour pressure of pure water at 298 K temperature is 18.4 m.m; if solution is prepared by adding a

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salt to that water, what will be the vapour pressure of this solution?

(a) 18.4 mm (b) 9.2 mm

(c) More than 18.4 mm (D) Less then 18.4 mm

Ans : (d)

1. An azeotropic solution of two liquids has boiling point lower than either of them when it

(a) Shows a negative deviation from Raoult’s law

(b) Shows no deviation from Raoult’s law

(c) Shows positive deviation from Raoult’s law

(d) Is saturated

Ans: (c) Shows positive deviation from Raoult’s law

2. The law of the relative lowering of vapour pressure was given by

(a) Raoult (b) Ostwald

(c) Van’t Hoff (d) Lewis

Ans: (a) Raoult

3. A solution that obeys Raoult’s law is

(a) Normal (b) Molar

(c) Ideal (d) Saturated

Ans: (c) Ideal

4. According to Raoult’s law, the relative lowering of vapour pressure of solution is equal to the

(a) Mole fraction of solute (b) Moles of solute

(c) Mole fraction of solvent (d) Moles of solvent

Ans: (a) Mole fraction of solute

5. The vapour pressure of benzene at a certain temperature is 640 mm of Hg. A non-volatile and

non-electrolyte solid weighing 2.175 g is added to 39.08 g of benzene. The vapour pressure of

the solution is 600 mm of Hg. What is the molecular weight of solid substance

(a) 49.50 (b) 59.6

(c) 69.5 (d) 79.8

Ans: (c) 69.5

Hint:

6. The vapour pressure of a solvent decreased by 10 mm of mercury, when a non-volatile solute

was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be

the mole fraction of the solvent, if decrease in the vapour pressure is to be 20 mm of mercury

(a) 0.8 (b) 0.6

(c) 0.4 (d) 0.2

Ans: (b) 0.6

Hint:

7. The vapour pressure of water at room temperature is 23.8 mm Hg. The vapour pressure of an

aqueous solutions of sucrose with mole fraction 0.1 is equal to

(a) 23.9 mm Hg (b) 24.2 Hg

(c) 21.42 mm Hg (d) 21.44 mm Hg

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Ans: (c) 21.42 mm Hg

Hint:

8. How many grams of a non-volatile solute having a molecular weight of 90 are to be dissolved in

97.5 g water in order to decrease the vapour pressure of water by 2.5 percent

(a) 25 (b) 18

(c) 12.5 (d) 9

Ans: (c) 12.5

Hint:

9. The vapour pressure of benzene at 90°C is 1020 torr. A solution of 5 g of a solute in 58.5 g

benzene has a vapour pressure of 990 torr. The molecular weight of the solute is

(a) 78.2 (b) 148.3

(c) 204.2 (d) 223.2

Ans: (d) 223.2

Hint:

10. An azeoptropic solution of two liquids has boing point lower than either when it

(a) Shows negative deviation from Raoult’s law

(b) Shows a positive deviation from raoult’s law

(c) Shows no deviation from raoult’s law

(d) Is saturated

Ans: (b) Shows a positive deviation from raoult’s law

11. The addition of a non-volatile solute to the solvent results in lowering of

(a) Vapour pressure as well as boiling point (b) Vapour pressure as well as density

(c) Vapour pressure as well as freezing point (d) Boiling point as well as freezing point

Ans: (c) Vapour pressure as well as freezing point

12. If X moles of a non-volatile solute is added to certain volume of the solvent with vapour

pressure P◦ so as to get a solution of vapour pressure P at the same temperature then P to

(a) X Po (b) Po X – Po

(c) Po(1 - X) (d) unpredictableAns: (c) Po(1 - X)

13. Vapour pressure of the solution of sodium chloride in water is

(a) Directly proportional to the mole fraction of water

(b) Inversely proportional to the mole fraction of NaCl

(c) Inversely proportional to the mole fraction of water

(d) Equal to the product of mole fraction of water and that of NaCl

Ans: (a) Directly proportional to the mole fraction of water

14. 100ml of liquid A and 25ml of liquid B is mixed to give a solution which does not obey Raoult’s

law. The volume of the solution

(a) Will be 125ml (b) Can be > or < than 125ml

(c) Can be greater than equal to or less than 125ml

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(d) Will be less than 125ml

Ans: (b) Can be > or < than 125ml

15. The vapour pressure of the solution of two liquids A (P◦ = 80 mm) and B (P◦ = 120 mm) is

found to be 100 mm when XA = 0.4 the result shows that

(a) Solution exhibits ideal behaviour (b) Solution shows positive deviation

(c) Solution shows negative deviation

(d) Solution will show positive deviation for lower concentrations and negative deviation for higher

concentration

Ans: (c) Solution shows negative deviation

16. Which of the following liquid pairs will exhibit a positive deviation from Raoult’s law ?

(a) Water – hydrochloric acid (b) cyclohexane – ethanol

(c) Acetone – chloroform (d) water – nitric acid

Ans: (b) cyclohexane – ethanol

17. Which of the following aqueous solution will have maximum lowering of vapour pressure?

(a) 0.1M NaCl (b) 0.1M FeCl3

(c) 0.1M Al2(SO4)3 (d) 0.1M BaCl2

Ans: (c) 0.1M Al2(SO4)3

18. According to Raoult’s law the relative lowering of vapour pressure of solution is equal to the

(a) Mole fraction of solute (b) mole fraction of solvent

(c) Moles of solute (d) moles of solvent

Ans: (a) Mole fraction of solute

19. 12g of urea is dissolved in 1 litre of water and 68.4g of sucrose is dissolved in 1 litre of water.

The lowering of vapour pressure of first solution is

(a) Equal to that of second (b) Greater than the second

(c) Less than the second (d) Double of the second

Ans: (a) Equal to that of second

20. Which of the following liquid pairs show a positive deviation from Raoult’s law?

(a) Benzene – methanol (b) Water – hydrochloric acid

(c) Water – nitric acid (d) Acetone – chloroform

Ans: (a) Benzene – methanol

21. Two liquids A and B form an ideal solution. At 300K the vapour pressure of a solution of 1

mole of A and x mole of B is 550mm. If the vapour pressures of pure A and B are 400mm and

600mm respectively then x is

(a) 1 (b) 2

(c) 3 (d) 4

Ans: (c) 3

22. If an ideal solution is made by mixing 2 moles of benzene (p◦ = 266mm) and 3 moles of

another liquid (p◦ = 236mm). The total vapour pressure of the solution at the same

temperature would be

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(a) 502 mm (b) 248 mm

(c) 600 mm (d) 250.6 mm

Ans: (b) 248 mm

23. Among equimolar solution of glucose, potassium chloride, calcium nitrate and ferric chloride.

the relative lowering of vapour pressure will be

(a) least for ferric chloride (b) equal for ferric chloride and potassium chloride

(c) least for glucose (d) highest for calcium nitrate

Ans: (c) least for glucose

24. The vapour pressure of pure water is 92.5mm at 300K. The vapour pressure of 1 molal

solution of X in water is

(a) 180 (b) 90.80

(c) 45.4 (d) unpredictable

Ans: (b) 90.80

25. Vapour pressure of CCl4 at 25 °C is 143 mm Hg. 0.5 gm of a non-volatile solute is dissolved in

100 ml CCl4. Find the vapour pressure of the solution. (density of CCl4 = 1.58)

(a) 141.93 mm (b) 94.39 mm

(c) 199.34 mm (d) 143.99mm

Ans: (b) 94.39 mm

26. The vapour pressure at a given temperature of an ideal solution containing 0.2 mol of a non-

volatile solute and 0.8 mol of a solvent is 60mm of Hg. The vapour pressure of the pure solvent

at the same temperature will be

(a) 120mm (b) 150mm

(c) 60mm (d) 75mm

Ans: (d) 75mm

27. An ideal solution was obtained by mixing methanol and ethanol. If the partial vapour pressure

of methanol and ethanol are 2.619 kPa and 4.556 kPa resp. the composition of vapour in terms

of mole fraction will be

(a) 0.635 MeOH, 0.365 EtOH (b) 0.365 MeOH, 0.635 EtOH

(c) 0.574 MeOH, 0.326 EtOH (d) 0.173 MeOH, 0.827 EtOH

Ans: (b) 0.365 MeOH, 0.635 EtOH

28. Benzene (p° = 160mm) and toluene (p° = 68mm of Hg) form ideal solution at certain

temperature with mole fraction of benzene as 0.2. The vapour pressure of solution will be

(a) 220mm (b) 86.4mm

(c) 160mm (d) unpredicted

Ans: (b) 86.4mm

29. Vapour pressure of a solvent decreased by 10mm of Hg when a non-volatile solute was added

to the solvent. The mole fraction of solute in solution is 0.2 what would be the mole fraction of

solvent if decreased in vapour pressure is 20mm of Hg?

(a) 0.8 (b) 0.6

(c) 0.4 (d) 0.2

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Ans: (c) 0.4

30. Vapour pressure of pure A is 70mm of Hg at 25°C. It forms an ideal solution with B in which

mole fraction of A is 0.8. If vapour pressure of solution is 84mm of Hg at 25°C the vapour

pressure of pure B at 25°C is

(a) 1atm (b) 14mm of Hg

(c) 140mm of Hg (d) 56mm of Hg

Ans: (c) 140mm of Hg

31. The vapour pressure of pure A and B at given temperature are 108 and 36 m bar resp what is

the mol fraction of B in the vapour phase of the solution containing equimolar mixture of A

and B

(a) 0.25 (b) 0.5

(c) 0.75 (d) 0.66

Ans: (a) 0.25

32. When one mole of non-volatile solute is dissolved in three moles of solvent the vapour

pressure of the solution relative to the vapour pressure of the pure solvent is

(a) ⅓ (b)1/4

(c) ¾ (d) 1

Ans: (b)1/4

33. The relative lowering of vapour pressure produced by 4 m solution of glucose in water

(vapour pressure of water = 22.5mm) is

(a) 0.067 (b) 0.166

(c) 1.665 (d) unpredictedAns: (a) 0.067

34. Which is correct about Henry’s law

(a) The gas in contact with the liquid should behave as an ideal gas

(b) There should not be any chemical interaction between the gas and liquid.

(c) The pressure applied should be high

(d) All of these

Ans: (b) There should not be any chemical interaction between the gas and liquid

Hint: Henry’s law is applicable for ideal solutions only.

35. Which of the following does not show positive deviation from Raoults law?

(a) Benzene – chloroform (b) Benzene – acetone

(c) Benzene - ethanol (d) Benzene - carbon tetrachloride

Ans: (a) Benzene – chloroform

36. 60 gm of urea (mol. wt. 60) was dissolved in 9.9 mole of water. If the vapour pressure of pure

water is Po, the vapour of solutions is

(a) 0.10 P0 (b) 1.10 P0 (c) 0.90 P0 (d) 0.99 P0

Ans: (c) 0.90 P0

Hint:

37. An azeotropic solution of two liquids has boiling point lower than either of two when it

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(a) Shows -ve deviation from Raoult’s law (b) shows, no deviation from Raoult’s

(c) Shows, +ve deviation from Raoult’s law (d) is saturated

Ans: (c) shows, +ve deviation from Raoult’s law

38. Vapour pressure of pure liquid A i.e PºA and B i.e., PºB are 100 mm and 150 mm Hg. Distillate of

vapours of a solution containing 2 mol. of A and 3 mol of B will have total vapour pressure ( on

condensation)

(a) ≈ 135 mm (b) ≈ 130 mm (c) ≈ 140 mm (d) ≈ 145 mm

Ans: (a) ≈ 135 mm

Hint: P = PAoXA

+ PBoXB

39. An azeotropic mixture of two liquids boils at a lower temperature than either of them when

(a) It is saturated

(b) It does not deviate from Raoult’s law

(c) It shows negative deviation from Raoult’s law

(d) It shows positive deviation from Raoult’s law Ans: (d) it shows positive deviation from Raoult’s law

40. Assertion: A solution of ethyl alcohol and water shows positive deviation from Raoult’s law

Reason: Due to positive deviation boiling point increase


(b) Both assertion and reason are correct, but reason is not correct explanation of the assertion.

(c) Assertion is correct, but reason is Incorrect.


Ans: (c) Assertion is correct, but reason is Incorrect.

41. Assertion: Non-ideal solutions showing negative deviation from Raoult’s law form

maximum boiling azeotrope.

Reason: Interaction between the components are different from those of the pure

component.






assertion

42. Assertion: A solution of ethyl alcohol and water shows positive deviational from Raoult’s

law

Reason: The solutions which have some vapour pressure at a given temperature are known

as isotonic solution.





Ans: (c) Assertion is correct, but reason is Incorrect.

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43. The vapour pressure of a solvent decreased by 10 mm Hg when a non volatile solute was

added to the solvent. The mole fraction of solute in solution is 0.2, what would be mole

fraction of the solvent if decrease in vapour pressure is 20 mm of Hg.

(a) 0.8 (b) 0.6

(c) 0.4 (d) 0.2

Ans: (b) 0.6

Hint: Po – Ps = Po × mole fraction of solute;

10 = Po × 0.2Again, 20 = Po × mole fraction solute

Hence, n = 0.4, so, mole fraction of solvent = 1 – 0.4 = 0.6

44. Which of the following liquid pairs shows a positive deviation from Raoult's law?

(a) Water-hydrochloric acid (b) Benzene-methanol

(c) Water-nitric acid (d) Acetone-chloroform

Ans: (b) Benzene-methanol

45. Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a

solution containing 78 g of benzene and 46 g of toluene in torr is -

(a) 25 (b) 50

(c) 53.5 (d) 37.5

Ans: (b) 50

Hint:

46. 18 g of glucose (C6H12O6) is added to 178.2 g of water. The vapour pressure of water for this

aqueous solution at 100° C is -

(a) 7.60 Torr (b) 76.00 Torr(c) 752.40 Torr (d) 759.00 Torr

Ans: (c) 752.40 Torr

Hint:

47. The vapour pressure of water at 20°C is 17.5 mm Hg. If 18 g of glucose (C6H12O6) is added to

178.2 g of water at 20°C, the vapour pressure of the resulting solution will be

(a) 17.675 mm Hg (b) 15.750 mm Hg

(c) 16.500 mm Hg (d) 17.325 mm Hg

Ans: (d) 17.325 mm HgHint:

48. Two liquids X and Y form an ideal solution. At 300K, vapour pressure of the solution

containing 1 mol of X and 3 mol of Y is 550 mm Hg. At the same temperature, if 1 mol of Y is

further added to this solution, vapour pressure of the solution increases by 10 mm Hg. Vapour

pressure (in mmHg) of X and Y in their pure states will be, respectively :-

(a) 400 and 600 (b) 500 and 600

(c) 200 and 300 (d) 300 and 400

Ans: (a) 400 and 600

Hint:

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49. On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the

two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour

pressure of the solution obtained by mixing 25.0 of heptane and 35 g of octane will be (molar

mass of heptane = 100 g mol.1 and of octane = 114 g mol.1) :-

(a) 144.5 kPa (b) 72.0 kPa

(c) 36.1 kPa (d) 96.2 kPa

Ans: (b) 72.0 kPa

Hint:

50. The vapour pressure of two liquids 'P' and 'Q' are 80 and 60 torr, respectively. The total

vapour pressure of solution obtained by mixing 3 mole of P and 2 mol of Q would be:

(a) 68 torr (b) 140 torr

(c) 72 torr (d) 20 torr

Ans: (c) 72 torr

Hint: P = Ppo.Xp + PQ

o.XQ

= 80 + 60

= 48 + 24 = 72 torr

51. A solution of acetone in ethanol

(a) shows a positive deviation from Raoult's law

(b) behaves like a near ideal solution

(c) Obeys Raoult's law

(d) shows a negative deviation from Raoult's law

Ans: (a) shows a positive deviation from Raoult's law

(8) What is the vapour pressure of a following solution:

0.02m sugar solution (x), 0.02 m urea solution (y) and 0.02m glucose (z)

(a) x = y = z (b) x > y > z (c) x < y < z (d) z < y < x Ans : (a)

ELEVATION IN BOILING POINT & DEPRESSION IN FRIZZING POINT

(72) Which is the unit of Kb?

(a) K.gram/lit. (b) K.gram/mole (c) K.kg/mole (d) K.kg.mole

Ans : (c)

(73) What is the vapour pressure of solution at its boiling point?

(a) 1 bar (b) 100 bar (c) 76 bar (d) None of theseAns : (a)

(74) Boiling point of the solution is...........than that of pure solvent.

(a) lower (b) equall (c) higher (d) not given

Ans : (c)

(75) Which statement is true for the solution prepared by adding salt (NaCl) to water?

(a) Freezing point increase, while boiling point decrease

(b) F.P and B.P both increase

(c) F.P and B.P both decrease

(d) Freezing point decrease, while boiling point increaseAns : (d)

(76) Which of the following is not a colligative properly?

b f

Ans : (d)

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(77) The decrease in the vapour pressure of solution is directly proprtional to which of the following?

(a) Kf (b) Depression in freezing point

(c) Kb (d) None of these

Ans : (b)

(78) What is the formula of molal depression constant?

(a)

0 b

w TK

M 1000

(b)

0T M wK

1000 w

f

(c) 0

T M wK

1000 w

f

(d)

0 0

0

T w MK

1000 w

f

Ans : (b)

(79) b and m?

(a) b bT K m

(b) b bK T M

(c) b bm K / T

(d) b bT K m

Ans : (a)

(80) What is the unit of Kf ?-1 (b) Kel

-1

Ans : (a)

1. Which one of the following would produce maximum elevation in boiling point?

(a) 0.1 M glucose (b) 0.2 M sucrose

(c) 0.1 M barium chloride (d) 0.1 M magnesium sulphate

Ans: (c) 0.1 M barium chloride

2. When a substance is dissolved in a solvent, the vapour pressure of the solvent is decreased. This

results in(a) An increase in the boiling point of the solution

(b) A decrease in the boiling point of solvent

(c) The solution having a higher freezing point than the solvent

(d) The solution having a lower osmotic pressure than the solvent

Ans: (a) An increase in the boiling point of the solution

3. Which of the following statements is correct for the boiling point of solvent containing a

dissolved solid substance?

(a) Boiling point of the liquid is depressed(b) Boiling point of the liquid is elevated

(c) There is no effect on the boiling point

(d) The change depends upon the polarity of liquid

Ans: (b) Boiling point of the liquid is elevated

4. The molal cryo-scopic constant for water is

(a) 1.86 K molality-1 (b) 5.26 K molality-1

(c) 55.5 K molality-1 (d) 0.52 K molality-1

Ans: (a) 1.86 K molality-1

5. Heavy water freezes at

(a) 0 °C (b) 3.8 °C

(c) 38 °C (d) − 0.38 °C

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Ans: (b) 3.8 °C

6. Which has the minimum freezing point?

(a) One molal NaCl solution (b) One molal KCl solution

(c) One molal CaCl2solution (d) One molal urea solution

Ans: (c) One molal CaCl2 solution

7. From the following which one has the highest molal freezing point.

(a) Urea (b) BaCl2

(c) KBr (d) Al2(SO4)3

Ans: (a) Urea

8. Which of the following has lowest freezing point?

(a) 0.1 M aqueous solution of glucose (b) 0.1 M aqueous solution of NaCl

(c) 0.1 M aqueous solution of ZnSO4 (d) 0.1 M aqueous solution of urea

Ans: (b) 0.1 M aqueous solution of NaCl

9. Which of the following will have the highest F.P. at one atmosphere?

(a) 0.1 M NaCl solution (b) 0.1 M sugar solution

(c) 0.1 M BaCl2 solution (d) 0.1 M FeCl3 solution

Ans: (b) 0.1 M sugar solution

10. The freezing point of 1 percent solution of lead nitrate in water will be

(a) Below 0°C (b) 0°C

(c) 1°C (d) 2°C

Ans: (a) Below 0°C

11. Which of the following will produce the maximum depression in freezing point of its aqueous

solution?

(a) 0.1 M glucose (b) 0.1 M sodium chloride

(c) 0.1 M barium chloride (d) 0.1 M magnesium sulphate

Ans: (c) 0.1 M barium chloride

Hint: BaCl2 dissociates to form 3 ions, more ions, greater depression.

12. If Kf value of H2O is 1.86. The value of ∆Tf for 0.1 m solution of non-volatile solute is(a) 18.6 (b) 0.186

(c) 1.86 (d) 0.0186

Ans: (b) 0.186

Hint: ΔTf = Kf . m

13. When mercuric iodide is added to the aqueous solution of potassium iodide, the

(a) Freezing point is raised (b) Freezing point is lowered

(c) Freezing point does not change (d) Boiling point does not change

Ans: (b) Freezing point is lowered

14. The freezing point of a dilute solution of acetamide in glacial acetic acid is 298 K. This is the

value when crystals of

(a) Acetamide first appears (b) Acetic acid first appears

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(c) Both appear together (d) Ice first appears

Ans: (b) Acetic acid first appears

15. The factor∆Tf /Kf represents

(a) Molarity (b) Formality

(c) Normality (d) Molality

Ans: (d) Molality

Hint: ΔTf = Kf . m

16. In cold countries, ethylene glycol is added to water in the radiations of cars during winter. This

results in

(a) Lowering of F.P. (b) Reducing the viscosity

(c) Reducing the specific heat (d) Making water a better conductor of electricity

Ans: (a) Lowering F.P

17. 10 g of solute with molecular mass 100 g mol−1

is dissolved in 100 g of solvent to show 0.3°

elevation in boiling point. The value of molal ebullioscopic constant will be

(a) 10 (b) 3

(c) 0.3 (d) Unpredictable

Ans: (c) 0.3

Hint: Kb =Δ

18. The freezing point of a 0.01 M aqueous glucose solution at 1 atmosphere is −0.18 oC . To it, an

addition of equal volume of 0.002 M glucose solution will produce a solution with freezing

point of nearly

(a) − 0.036 °C (b) − 0.108 ° C

(c) − 0.216 °C (d) − 0.422 °C

Ans: (c) – 0.216 °C

Hint: Kf =Δ

19. The freezing point of 0.05 molal solution of a non-electrolyte in water is

(a) - 1.86° C (b) - 93° C

(c) - 0.093° C (d) 0.93° C

Ans: (c) -0.0930

CHint: Kf =

Δ

20. What is the molality of solution of a certain solute in a solvent, if there is a freezing point

depression of 0.184°C and if the freezing point constant is 18.4?

(a) 0.01 (b) 1

(c) 0.001 (d) 100

Ans: (a) 0.01

Hint: ΔTf = Kf . m

21. A 0.5 molal solution of ethylene glycol in water is used as coolant in a car. If the freezing point

constant of water be 1.86°C per mole, the mixture shall freeze at

(a) 0.93 °C (b) - 0.93 °C

(c) 1.86 °C (d) - 1.86 °C

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Ans: (b) - 0.93°C

Hint: Kf =Δ

22. 8 g of HBr is added in 100 g of H2O. The freezing point will be (K f = 1.86, H = 1, Br = 80)

(a) - 0.75°C (b) 0°C

(c) - 3.67°C (d) - 7.6°C

Ans: (c) - 3.67°C

Hint: Kf =Δ

23. An experimenter tries to determine the molecular weight of glucose by observing the depression

in freezing point. He carries out his experiment in duplicate. In one he uses pure water as the

solvent and in the other experiment, by mistake he uses a 0.1N aqueous NaCl as the solvent. It is

expected that he will report

(a) Same results in both the cases

(b) A higher value of molecular weight of glucose in the second case

(c) A lower value of molecular weight of glucose in the second case(d) An average of molecular weights of glucose and sodium chloride in the second case

Ans: (c) A lower value of molecular weight of glucose in the second case

24. When mercuric iodide is added to the aqueous solution of KI the

(a) freezing point is raised (b) freezing point is lowered

(c) Boiling point does not change (d) freezing point does not change

Ans: (a) freezing point is raised

25. The ebullioscopic constant for water is 0.513°C kg/mole. The aqueous solution of sugar

containing 0.1 mole of it 200g of water will boil under a pressure of one atm at

(a)100.513 °C (b) 100.0513 °C

(c) 100.256 °C (d) 101.025 °C

Ans: (c) 100.256 °C

26. The relative lowering of vapour pressure of a solution containing 6 g of urea dissolved in 90 g of

water is

(a) 0.0196 (b) 0.05

(c) 1.50 (d) 0,01

Ans: (a) 0.0196

27. Assuming all the solution to be equi molal the one with highest freezing point is

(a) La(NO3)3 (b) glucose

(c) Ca(NO3)3 (d) C6H5NH3Cl

Ans: (b) glucose

28. The molal elevation constant of a liquid is the ratio of elevation in boiling point to

(a) Molality (b) normality

(c) Molarity (d) mole fraction of the solvent

Ans: (a) Molality

29. On cooling the dilute aqueous solution of sucrose below its freezing point what will be observed

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(a) ice will start separating out

(b) sugar will crystallise out

(c) solution will freeze as such with same composition

(d) water and sugar in frozen part will be present in stoichiometric ratio of 1:1

Ans: (a) ice will start separating out

30. Which of the following has the lowest freezing point?

(a) 1% glucose (b) 1% sucrose

(c) 1% KCl (d) 1% BaCl2

Ans: (d) 1% BaCl2

31. The ratio of elevation in boiling point of aqueous solution of sodium chloride to that of an

aqueous solution of glucose of same molalities is approximately

(a) 1 (b) 2

(c) 0.5 (d) 2.5

Ans: (b) 2

32. Which of the following solution will have highest value of depression in freezing point?

(a) 6% aqueous solution of glucose (b) 6% aqueous solution of urea

(c) 6% aqueous solution of sucrose (d) all the above will have same value

Ans: (d) all the above will have same value

33. The freezing point of 1 percent solution of lead nitrate in water at one atm. pressure will be

(a) below 273K (b) 273K

(c) 274K (d) 275K

Ans: (a) below 273K

34. Which of the following 0.10 m aqueous solution will have lowest freezing point?

(a) KCl (b) Al2(SO4)3

(c) Glucose (d) sugar

Ans: (b) Al2(SO4)3

35. Molal depression constant for water is 1.86°C. The freezing point of a 0.05 molal solution of a

non-electrolyte in water is

(a) – 1.86°C (b) – 0.93°C

(c) – 0.093°C (d) 0.93°C

Ans: (c) – 0.093°C

36. Dissociation of 1g of certain compound X in 250g of water produce a depression in its freezing

point by 0.124◦C. if freezing constant for water is 1.86 the molecular mass of X

(a) 180 (b) 60

(c) 90 (d) 30

Ans: (b) 60

37. What is the freezing point of a solution containing 8.1 g HBr in 100g water assuming the acid to

be 90% ionised (depression constant is 1.86 )

(a) 0.85 ◦C (b) -3.53 ◦C

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(c) 0 ◦C (d) -0.35 ◦C

Ans: (b) -3.53 ◦C

38. The normal boiling point of water is 373 K (at 700mm). Vapour pressure of water at 298K is 23

mm. If enthalpy of vaporization is 40.656 kJ/mol the boiling point of water at 23 mm pressure

will be

(a) 250K (b) 298K

(c) 51.6K (d)12.5KAns: (b) 298K

39. The mass of glucose that should be dissolved in 100g water in order to produce same lowering

of vapour pressure as is produced dissolving 1g of urea in 50g of water is

(a) 1g (b) 2g

(c) 6g (d) 12g

Ans: (c) 6g

40. In the depression of freezing point experiment, it is found that the(a) The vapour pressure of the solution is less than that of pure solvent

(b) The vapour pressure of the solution is more than that of pure solvent

(c) Only solute molecules solidify at the freezing point

(d) Both solute and solvent molecules solidify the freezing point.

Ans: (a) The vapour pressure of the solution is less than that of pure solvent.

41. Pressure cooker reduces cooking time for food because

(a) Heat is more evenly distributed in the cooking space

(b) Boiling point of water involved in cooking is increased(c) The higher pressure inside the cooker crushes the food material

(d) Cooking involves chemical changes helped by a rise in temperature

Ans: (b) Boiling point of water involved in cooking is increased

42. What is the effect of the addition of sugar on the boiling and freezing points of water?

(a) Both boiling point and freezing point increases

(b) Both boiling point and freezing point decreases

(c) Boiling point increases and freezing point decreases

(d) Boiling point decreases and freezing point increases

Ans: (c) Boiling point increases and freezing point decreases

43. Increase in b.pt. of aqueous solution of sucrose solution is 0.1K. The increase in the b.pt of

aqueous NaCl solutions of same concentration of approximately.

(a) 0.1K (b) 0.2K

(c) 0.3K (d) 0.05 K

Ans: (b) 0.2 K

Hint: Double because, ionic conc. of NaCl is twice that of sucrose

44. In cold climate water gets frozen causing damage to the radiator of a car. Ethylene glycol is

used as anti freezing agent. Calculate the amount of ethylene glycol to be added to 4 kg of water to

prevent it from freezing at -6ºC (Kf for water = 1.85 km-1)

(a) 804.3 g (b) Half the amount of water

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(c) one-fourth the amount of water (d) 402.1 g

Ans: (a) 804.3 g

Hint: Kf =Δ

45. Maximum freezing point will be of molal solution of (assuming equal ionisation in each case)

(a) [Cr(H2O)6]Cl3 (b) [CrCl (H2O)5]Cl2 H2O

(c) [CrCl2 (H2O)4] Cl 2H2O (d) [Fe(H2O) Cl3] 3H2O

Ans: (d) [Fe(H2O) Cl3] 3H2O

46. The molal freezing point constant for water is 1.86ºC m-1. The freezing point of 0.1 m NaCl solution

is expected to be

(a) -1.86ºC (b) - 0.372ºC

(c) 0.186ºC (d) 0.372ºC

Ans: (b) - 0.372ºC

Hint: ΔTf = Kf .m.i =1.86 x 0.1 x 2 = 0.372 oC

Now, FP = 0oC - 0.372 OC = -0.372oC

47. The molal elevation constant of water is 0.51 the b.pt of 0.1 molal aqueous NaCl solution is nearly

(a) 100.05 ºC (b) 100.1 ºC

(c) 100.2 ºC (d) 101.0 ºC

48. Ans: (b) 100.1ºC Assertion: 0.01 M solution of urea and glucose will freeze at same

temperature.

Reason: Freezing point of solution is inversely proportional to the concentration of the solution.



(c) Assertion is correct, but reason is Incorrect.(d) Assertion is Incorrect, but reason is correct.

Ans: (b) Both assertion and reason are correct, but reason is not correct explanation of the

assertion.

49. Assertion: An aques solution of sodium chloride freezes at lower temperature than water but

boils at higher tempr. than water

Reason: By the addition of sodium chloride in water vapoure pressure of solution increases.


(b) Both assertion and reason are correct, but reason is not correct explanation of the assertion.(c) Assertion is correct, but reason is Incorrect.


Ans: (b) Both assertion and reason are correct, but reason is not correct explanation of the

assertion.

50. The molal freezing point constant for water is 1.86 K. molarity–1. If 34.2 g of cane sugar

(C12H22O11) are dissolved in 1000g of water, the solution will freeze at

(a) –1.86 °C (b) 1.86 °C

(c) –3.92 °C (d) 2.42 °CAns: (a) – 1.86°c

Hint:

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51. 20 g of a binary electrolyte (mol wt. = 100) are dissolved in 500 g of water. The freezing of the

solution is –0.74°C, Kf = 1.86 K.molality-1 The degree of ionisation of the electrolyte is

(a) 50% (b) 75%

(c) 100% (d) 0

Ans: (d) 0

Hint:

So, α = 0.

52. The freezing point of aqueous solution contains 5% by mass urea, 1.0% by mass KCl and 10%

by mass of glucose is : (Kf(H2O)= 1.86K molality–1)

(a) 290.2 K (b) 285.5 K(c) 269.93 K (d) 250 K

Ans: (c) 269.93 K

Hint:

53. For an aqueous solution, freezing point is 0.186°C. The boiling point of the same solution is (Kf

= 1.86° mol.1 kg) and (Kb=0.512 mol. 1 kg)(a) 0.186° (b) 100.0512

(c) 1.86° (d) 5.12°

Ans: (b) 100.0512°

Hint:ΔΔ

∴ ΔTb =

oC

∴ Boiling Point = 100 + 0.0512 = 100.0512 oC

54. A pressure cooker reduces cooking time for food because -

(a) The higher pressure inside the cooker crushes the food material

(b) Cooking involves chemical changes helped by a rise in temperature

(c) Heat is more evenly distributed in the cooking space

(d) Boiling point of water involved in cooking is increased

Ans: (d) Boiling point of water involved in cooking is increased

55. In a 0.2 molal aqueous solution of a weak acid HX the degree of ionization is 0.3. Taking kf for

water as 1.85, the freezing point of the solution will be nearest to,

(a) - 260°C (b) + 0.480°C

(c) - 0.480°C (d) - 0.360°CAns: (c) - 0.480°C

Hint: α =

∴ i = (0.3 x 1) + 1 = 1.3

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Now,

ΔTf = Kf .m.i

= 1.85 x 0.2 x 1.3 = 0.48 oC

∴ Freezing point = 0 – 0.48 = -0.48 oC

56. Which one of the following statement is False?

(a) Raoult's law states that the vapour pressure of a component over a solution is proportional

to its mole fraction(b) The osmotic pressure (π) of a solution is given by the equation π = MRT where M is the

molarity of the solution

(c) The correct order of osmotic pressure for 0.01M aqueous solution of each compound is BaCl2

> KCl > CH3COOH > Sucrose

(d) Two sucrose solutions of same molality prepared in different solvent will have the same

freezing point depression

Ans: Two sucrose solutions of same molality prepared in different solvent will have the same

freezing point depression

57. Equi-molar solutions in the same solvent have -

(a) Same freezing point but different boiling point

(b) Same boiling point but different freezing point

(c) Different boiling and different freezing point

(d) Same boiling and same freezing points

Ans: (d) Same boiling and same freezing points

58. If sodium sulphate is considered to be completely dissociated into cations and anions in

aqueous solution, the change in freezing point of water (ΔTf ), when 0.01 mol of sodium

sulphate is dissolved in 1 kg of water, is (Kf = 1.86 K kg mol.1) :-

(a) 0.0186 K (b) 0.0372 K

(c) 0.0558 K (d) 0.0744 K

Ans: (c) 0.0558 K

Hint: ΔTf = Kf . m. i

59. Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should

be added to 4 kg of water to prevent it from freezing at -6°C will be : (Kf for water = 1.86 K

kgmol-1, and molar mass of ethylene glycol = 62 gmol-1)

(a) 400.00 g (b) 304.60 g

(c) 804.32 g (d) 204.30 g

Ans: (c) 804.32 gHint: ΔTf =

60. Camphor is often used in molecular mass determination because:

(a) It has a very high cryoscopic constant (b) It is volatile

(c) It is solvent for organic substances (d) It is readily available

Ans: (a) It has a very high cryoscopic constant

61. A solution of urea (mol. mass 56 g mol-1) boils at 100.18°C at the atmospheric pressure. If Kf

and Kb for water are 1.86 and 0.512K kg mol-1 respectively, the above solution will freeze at

(a) 6.54°C (b) 0.654°C (c) 6.54°C (d) 0.654°C

Ans: (b) 0.654°C

Hint: ΔTf =

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62. 1.00g of a non-electrolyte solute (molar mass 250g mol-1) was dissolved in 51.28 of benzene. If

the freezing point depression constant, Kf of benzene is 5.12 K kg mol-1, the freezing point of

benzene will be lowered by :

(a) 0.4 K (b) 0.3 K (c) 0.5 K (d) 0.2 K

Ans: (a) 0.4 K

Hint: ΔTf =

63. 0.5 molal aqueous solution of a weak acid (HX) is 20% ionised. If Kf for water is 1.86 K kg mol-

1, the lowering in freezing point of the solution is :

(a) -0.56 K (b) -1.12 K (c) 0.56 K (d) 1.12 K

Ans: (d) 1.12 K

Hint: ΔTf = Kf . m. i

(108) What is the vapour pressure of solution at its boiling point?

(a) 1 atmosphere (b) 0 atmosphere (c) 100 atmosphere (d) 76 atmosphere

Ans : (a)

(4) Calculate T of the solution of 90 gram glucose in 1 kg. solvent. bK 0.35ºC kg/mole.

(a) 175º C (b) 0.175º C (c) 1.75º C (d) 17.5º C

Ans : (b)

Mole of glucose90 1

(m)180 2

mole

\ Increase in temperate also be1

2.

bK 0.35T 0.175º2 2

C

(5) What is the boiling point of the 2 molal glucose solution. ( bK 4º C kg/mole)

(a) 108º C (b) 100º C (c) 180º C (d) 80º C

Ans : (a)

b

TK

m

bT K m 4 2 8º C

(6) By adding how much urea to 500 gram water, the volume of depression in freezing point (T) will be f / 2K ?


Ans : (d)

By adding 60 gram urea to 1 kg. water, 1 m solution is formed and f T K

for f K

2,

60

2= 30 gram urea should dissolve in 1 kilogram solvent. Here solvent is 500 gram and hence

3015

2 gram substance is requied.

(7) The elevation in boiling point of solution prepared in 250 gram water is equal to K b. How much KC1 isdissolved in it

(a) 74.5/8 (b) 74.5 2 (c) 74.5 (d) 74.5 4

Ans : (a)

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OSMOSIS, DETERMINATION OF MOLECULAR MASS AND VAN’T HOFF FACTOR

1. Among the following substance the lowest vapour pressure is exerted by

(a) Water (b) Mercury

(c) Kerosene (d) Rectified spirit Ans: (b) Mercury

2. Which has maximum vapour pressure?

(a) HI (b) HBr

(c) HCl (d) HF

Ans: (c) HCl

3. Which of the following solution in water possesses the lowest vapour pressure?

(a) 0.1 M NaCl (b) 0.1 N BaCl2

(c) 0.1 M KCl (d) None of these

Ans: (b) 0.1 N BaCl2

Hint: More the ions produced on dissociation higher the depression in FP, hence lower

the FP

4. At higher altitudes the boiling point of water lowers because

(a) Atmospheric pressure is low (b) Temperature is low

(c) Atmospheric pressure is high (d) None of these

Ans: (a) Atmospheric pressure is low

5. Molecular mass of CHCl3 can be determined by

(a) Osmotic pressure (b) Rast method

(c) Both the above (d) None of the above

Ans: (d) None of the above

6. The melting points of most of the solid substances increase with an increase of pressure

acting on them. However, ice melts at temperature lower than its usual melting point, when

the pressure increases. This is because(a) Ice is less denser than water (b) Pressure generates heat

(c) The bonds break under pressure (d) Ice is not a true solid

Ans: (b) pressure generates heat

7. At a suitable pressure near the freezing point of ice, there exists

(a) Only ice (b) Ice and water

(c) Ice and steam (d) Ice, water and steam, all existing side by side

Ans: (d) Ice, water and steam, all existing side by side

8. Isotonic solutions have

(a) Equal temperature (b) Equal osmotic pressure

(c) Equal volume (d) Equal amount of solute

Ans: (b) Equal osmotic pressure

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9. At the same temperature which of the following solution will be isotonic

(a) 3.24 g of sucrose per litre of water and 0.18 gm glucose per litre of water

(b) 3.42 gm of sucrose per litre and 0.18 gm glucose in 0.1 litre of water

(c) 3.24 g of sucrose per litre of water and 0.585 gm of sodium chloride per litre of water

(d) 3.42 gm of sucrose per liter of water and 1.17 gm of sodium chloride per litre of water

Ans: (b) 3.42 gm of sucrose per litre and 0.18 gm glucose in 0.1 litre of water

10. In osmosis(a) Solvent molecules move from higher concentration to lower concentration

(b) Solvent molecules move from lower to higher concentration

(c) Solute molecules move from higher to lower concentration

(d) Solute molecules move from lower to higher concentration

Ans: (b) Solvent molecules move from lower to higher concentration

11. Semi-permeable membrane is that which permits the passage of

(a) Solute molecules only (b) Solvent molecules only

(c) Solute and solvent molecules both (d) neither solute nor solvent moleculesAns: (b) Solvent molecules only

12. At constant temperature, the osmotic pressure of a solution

(a) Directly proportional to the concentration

(b) Inversely proportional to the concentration

(c) Directly proportional to the square of the concentration

(d) Directly proportional to the square root of the concentration

Ans: (a) Directly proportional to the concentration

13. The osmotic pressure of a solution is given by the relation

(a) π = RT / C (b) π = CT / R

(c) π = RC / T (d) π / C = RT

Ans: (d) π / C = RT

Hint: π = CRT

14. The osmotic pressure of solution increases if

(a) Temperature is decreased

(b) Solution concentration is increased

(c) Number of solute molecules is increased

(d) Volume is increased

Ans: (c) Number of solute molecules is increased

15. The osmotic pressure of a dilute solution of a non-volatile solute is

(a) Directly proportional to its temperature on the centigrade scale

(b) Inversely proportional to its temperature on the Kelvin scale

(c) Directly proportional to its temperature on the Kelvin scale

(d) Inversely proportional to its temperature on the centigrade scale

Ans: (c) Directly proportional to its temperature on the Kelvin scale

16. At low concentrations, the statement that equi-molal solutions under a given set of

experimental conditions have equal osmotic pressure is true for

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(a) All solutions (b) Solutions of non-electrolytes only

(c) Solutions of electrolytes only (d) None of these

Ans: (a) All solutions

17. If a 0.1 M solution of glucose (mol. wt. 180) and 0.1 molar solution of urea (mol. wt. 60)

are placed on the two sides of a semi-permeable membrane to equal heights, then it will be

correct to say

(a) There will be no net movement across the membrane

(b) Glucose will flow across the membrane into urea solution(c) Urea will flow across the membrane into glucose solution

(d) Water will flow from urea solution into glucose solution

Ans: (a) There will be no net movement across the membrane

18. One mole each of urea, glucose and sodium chloride were dissolved in one litre of water

equal osmotic pressure will be produced by solutions of

(a) Glucose and sodium chloride (b) Urea and glucose

(c) Sodium chloride and urea (d) None of these

Ans: (b) Urea and glucose

19. If 3gm of glucose (mol. wt. 180) is dissolved in 60 gm of water at 15 o C. Then the osmotic

pressure of this solution will be

(a) 0.34 atm (b) 0.65 atm

(c) 6.57 atm (d) 5.57 atm

Ans: (c) 6.57 atm

Hint: π =

20. The solution in which the blood cells retain their normal form are with regard to the blood(a) Isotonic (b) Isomotic

(c) Hypertonic (d) Equinormal

Ans: (a) Isotonic

21. The osmotic pressure in atmospheres of 10% solution of cane sugar at 69 o C

(a) 724 (b) 824

(c) 8.21 (d) 7.21

Ans: (c) 8.21

22. The osmotic pressure of a 5% (wt/vol) solution of cane sugar at 150 o C

(a) 2.45 atm (b) 5.078 atm

(c) 3.4 atm (d) 4

Ans: (d) 4

23. The value of osmotic pressure does not depend upon

(a) Concentration of the solution

(b) Temperature of the solution

(c) Number of the particles of the solute present (d) Structure of the solute particles

Ans: (d) Structure of the solute particles

24. A glucose solution is to be injected into the blood stream. It must have the same as the blood

stream

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(a) Molarity (b) Vapour pressure

(c) Osmotic pressure (d) Viscosity

Ans: (c) Osmotic pressure

25. Increase in boiling point of a sucrose solution is 0.1 K, then what is increase in boiling point

of the same concentration of NaCl solution

(a) 0.1K (b) 0.2 K

(c) 0.4 K (d) 0.58 KAns: (b) 0.2 K

Hint: Van’t Hoff factor (i) = 2

26. The boiling point of water (100o C) becomes 100.52 o C. If 3 grams of a non-volatile solute

is dissolved in 200 ml of water. The molecular weight of solute is ( Kb for water is 0.6 K − m )

(a) 12.2 g mol-1 (b) 15.4 g mol-1

(c) 17.3 g mol-1 (d) 20.4 g mol-1

Ans: (c) 17.3 g mol-1

Hint: M = Δ

27. The latent heat of vaporisation of water is 9700 cal/mole and if the b.p. is 100 o C ,

ebullioscopic constant of water is

(a) 0.513°C (b) 1.026°C

(c) 10.26°C (d) 1.832°C

Ans: (a) 0.513 0 C

Hint: Kb =Δ

28. The boiling point of a solution of 0.1050 gm of a substance in 15.84 gram of ether was found

to be 0.100 o C higher than that of pure ether. What is the molecular weight of the substance

[Molecular elevation constant of ether per 100 g = 21.6 ]

(a) 144.50 (b) 143.18

(c) 140.28 (d) 146.66

Ans: (b) 143.18

Hint: M =

Δ

29. Boiling point of chloroform was raised by 0.323 K, when 0.5143 g of anthracene wasdissolved in its 35g. Molecular mass of anthracene is (Kb for CHCl3 = 3.9k −kgmol−1)

(a) 79.42 g / mol (b) 132.32 g / mol

(c) 177.42 g / mol (d) 242.32 g / mol

Ans: (c) 177.42 g/mol

Hint: M =

Δ

30. 0.15 gm of a substance dissolved in 15 g of solvent, boiled at a temperature higher by

0.216°C than that of the pure solvent. Find out the molecular weight of the substance (Molal

elevation constant for the solvent is 2.16°C)

(a) 1.01 (b) 10.1

(c) 100 (d) 10

Ans: (c) 100

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Hint: M =

Δ

31. 10% aqueous solution of certain substance is isotonic with 5% aqeous solution of fructose. The

molecular mass of the substance is

(a) 90u (b) 360u

(c) 180u (d) 540u

Ans: (b) 360u

32. The vapour pressure of a solution of 5g of non-electrolyte in 100 g of water at a particular

temperature is 2985 . The vapour pressure of pure water is 3000. the molecular mass of

solute is

(a) 180 (b) 120

(c) 60 (d) 392

Ans: (a) 180

33. A 5% solution of sugarcane (MW = 342) is isotonic with 1% solution of substance X. The

molecular weight of X is

(a) 171.2 (b) 68.4

(c) 34.2 (d) 136.2

Ans: (b) 68.4

34. Certain substance trimerises when dissolved in a solvent A. The van’t hoff factor ‘i’ for the

solutions is

(a) 1 (b) 1/3

(c) 3 (d) unpredictable

Ans: (b) 1/3

35. A non-volatile solute is found to dissociate in aqueous solution the van’t hoff factor i will be

(a) > 1 (b) < 1

(c) =1 (d) = 0

Ans: (a) > 1

36. For a solution of a non-electrolyte in water the van ‘t hoff factor is always

(a) = 0 (b) < 1(c) = 2 (d) > 1 but < 2

Ans: (b) < 1

37. For 0.7 M aqueous solution of certain electrolyte the osmotic pressure

(a) is independent of temperature (b) increase with increase in temperature

(c) Decrease with decrease in temperature

(d) First increase and then decrease with rise in temperature

Ans: (b) increase with increase in temperature

38. The osmotic pressure of 10% aqueous solution of urea (π1) is related to that of 10% aqueous

solution of glucose (π2) as

(a) π1 = π2 (b) π1 > π2

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(c) π1 < π2 (d) π1 = 1 – π2

Ans: (b) π1 > π2

39. The osmotic pressure of a dilute solution is directly proportional to the

(a) Diffusion rate of the solute (b) ionic concentration

(c) Elevation in boiling point

(d) Flow of solvent from a concentration to a dilute solution

Ans: (b) ionic concentration

40. Two solution is separated with semi-permeable membrane. solution B has greater vapour

pressure than solution A water will flow from

(a) A to B (b) B to A

(c) No flow of water (d) direction of flow cannot be predicted

Ans: (b) B to A

41. Solution with same vapour pressure are called

(a) isotonic (b) isopiestic(c) hypertonic (d) isomorphic

Ans: (b) isopiestic

42. osmotic pressure of a solution increases by

(a) decrease the temperature (b) increasing the volume

(c) increasing the number of molecules of solute

(d) increasing the number molecule of solvent

Ans: (c) increasing the number of molecules of solute

43. At 25°C the highest osmotic pressure is exhibited by 0.1 M solution of

(a) CaCl2 (b) KCl

(c) glucose (d) urea

Ans: (a) CaCl2

44. Van’t hoff factor for Ca(NO3)2 is

(a) 1 (b) 2

(c) 3 (d) 4

Ans: (c) 3

45. Benzoic acid undergoes dimerisation in benzene solution. The van’t hoff factor ‘i’ is related

to the degree of association ‘α’ of acid as

(a) i = 1 – α (b) i = 1 + α

(c) i = 1 – α/2 (d) i = 1 + α/2

Ans: (c) i = 1 – α/2

46. The value of observed and theoretical molecular masses of certain electrolyte XY are 65.4

and 114.45 resp. The electrolyte XY in the solution has dissociation to the extent of (a) 75% (b) 80%

(c) 50% (d) 90%

Ans: (a) 75%

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47. At 300K the two solution of glucose A and B with resp. concentration 0.01M and 0.001M are

separated by semipermeable membrane. How much external pressure need to be applied

and on which solution so as to prevent osmosis?

(a) 0.2463 atm pressure is applied on solution B

(b) 0.2217 atm pressure is applied on solution A

(c) 0.0246 atm pressure is applied on solution B

(d) 0.0217 atm pressure is applied on solution A

Ans: (b) 0.2217 atm pressure is applied on solution A

48. Which of the following solution are expected to be isotonic with respect to 0.6% (W/V)

solution of urea

I. 1.8% solution of glucose

II. 0.1M solution of NaCl

III. 0.1M solution of sucrose

IV. 0.1M solution of acetic acid

(a) I ,III (b) I, II, III

(c) II, IV (d) II, III

Ans: (d) II, III

49. Which one of the following salts will have the same value of van’t hoff factor (i) as that of

K4[Fe(CN)6]

(a) Al2(SO4)2 (b) NaCl

(c) Al(NO3)2 (d) Na2SO4

Ans: (a) Al2(SO4)2

50. A solution containing 6.8g of non-ionic solute in 100g of water was found to freeze at -0.93°C.

If depression constant of water is 1.86. The molecular mass of solute is

(a) 13.6 (b) 34

(c) 68 (d) 136

Ans: (d) 136

51. The osmotic pressure of 5% solution of sugar cane at 150°C (MM = 342) is

(a) 4atm (b) 5.07 atm

(c) 3.55 atm (d) 2.45 atm

Ans: (b) 5.07 atm

52. The relationship between osmotic pressure at 273K when 10g glucose (P1), 10g urea (P2)

and 10g sucrose (P3) are dissolved in 250ml of water is

(a) P1 > P2 > P3 (b) P3 > P1 > P2

(c) P2 > P1 > P3 (d) P2 > P3 > P1

Ans: (c) P2 > P1 > P3

53. What will be the osmotic pressure of 0.05M solution of sucrose at 5°C?

(a) 1.14 atm (b) 2.07 atm(c) 1.05 atm (d) 3.05 atm

Ans: (a) 1.14 atm

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54. If 0.15 g of solute dissolved in 15 g of solvent is boiled at temperature higher by 0.216 oC

than that of pure solvent the molecular mass of substance is (molal elevation constant for

solvent is 2.16 K/m)

(a) 1.01 (b) 10

(c) 10.1 (d) 100

Ans: (d) 100

55. If each of the following salts dissociate in aqueous solution to the extent of 90% than the onewith highest osmotic pressure would be

(a) Decimolar solution of Al2(SO4)3 (b) Decimolar solution of Na2SO4

(c) Decimolar solution of BaCl2 (d) Decimolar solution of NaCl

Ans: (a) Decimolar solution of Al2(SO4)3

56. The molecular mass of NaCl was determined to be 31.8 by cryoscopic method. The degree of

dissociation of NaCl in solution is approximately

(a) 62.5% (b) 50%

(c) 100% (d) 84%Ans: (d) 84%

57. 0.15g of a substance dissolved in 15g of a solvent boiled at a temp higher by 0.216◦ than that

of the pure solvent. Find out the molecular mass of the substance. (elevation constant is

2.16)

(a) 1.01 (b) 10.1

(c) 100 (d) 10

Ans: (c) 100

58. Osmotic pressure of 30% solution of glucose is 1.20 bar and that of 3.42% solution of cane

sugar is 2.5 bar. The osmotic pressure of the mixture containing equal volumes of two

solution will be

(a) 2.5 atm (b) 3.7 atm

(c) 1.85 atm (d) 1.3 atm

Ans: (c) 1.85 atm

59. 0.6g of a solute is dissolved in 0.1L of a solvent which develops an osmotic pressure of 1.23

atm at 300K. The molecular mass of the substance is(a) 149.5 (b) 120

(c) 430 (d) none

Ans: (b) 120

60. Acetic acid exists in benzene solution in dimeric form. In a actual experiment the van’t hoff

factor was found to be 0.52. the degree od association of acetic acid

(a) 0.48 (b) 0.88

(c) 0.96 (d) 0.52

Ans: (c) 0.96

61. At certain temperture the osmotic pressure of an aqueous solution of urea was found to be

405 mm how many times the solution should be dilute in order to exhibit the osmotic

pressure of 81 mm at the same temperature?

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(a) 2 times (b) 4 times

(c) 8 times (d) 5 times

Ans: (d) 5 times

62. In a solution of A in B, A tetramerises as 4A→A4 If degree of association is 30% the van’t hoff

factor is approximately

(a) 0.775 (b) ¼

(c) 4 (d) unpredictableAns: (a) 0.775

63. What is van’t hoff factor of a mono-protic acid HX in its aqueous solution whose

concentration is 1 x 10-2 M given pKa of acid as 4

(a) 1.01 (b) 2.1

(c) 1.2 (d) 1.1

Ans: (d) 1.1

64. Which of the following has highest value of van’t hoff factor? (a) K2SO4(40% ionised) (b) KBr (50% ionised)

(c) K4[Fe(CN)6] (20% ionised) (d) FeCl3 (30% ionised)

Ans: (d) FeCl3 (30% ionised)

65. 0.5 M aqueous solution of glucose is isotonic with

(a) 0.5 M KCl (c) 0.5 M CaCl2

(c) 0.5 M urea (d) 1 M sucrose

Ans: (c) 0.5 M urea

66. Isotonic solution have the same

(a) Density (b) Molar concentration

(c) Normality (d) None of these

Ans: (b) Molar concentration

67. At 25oC, the highest osmotic pressure is exhibited by 0.1M solution of

(a) CaCl2 (b) KCl

(c) Glucose (d) Urea

Ans: (a) CaCl2

68. Osmotic pressure is 0.0821 atm at temperature of 300 K . Find concentration in mole/litre

(a) 0.033 (b) 0.066

(c) 0.33 × 10−2 (d) 3

Ans: (c) 0.33 × 10−2

Hint: π = CRT

69. The boiling point of a solution of 0.11 gm of a substance in 15 gm of ether was found to be

0.1°C higher than that of the pure ether. The molecular weight of the substance will be(a) 148 (b) 158

(c) 168 (d) 178

Ans: (b) 158

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Hint: M =

Δ

70. When 10 g of a non-volatile solute is dissolved in 100 g of benzene, it raises boiling point

by 1°C then molecular mass of the solute is (Kb for benzene = 2.53 k-m-1)

(a) 223 g (b) 233 g

(c) 243 g (d) 253 g

Ans: (d) 253 g

Hint: M =

Δ

71. The vant Hoff factor for 0.1 M Ba(NO3)2 solution is 2.74. The degree of dissociation is

(a) 91.3% (b) 87%

(c) 100% (d) 74%

Ans: (b) 87%

Hint: α =( – )

72. Benzoic acid undergoes dimerisation in benzene solution. The vant Hoff’s factor (i) is related

to the degree of association (α) of the acid as

(a) (i) = (1 - α) (b) (i) = (1 + α)

(c) (i) = (1 - α/2) (d) (i) = (1 + α/2)

Ans: (c) (i) = (1 - α/2)

Hint: α =( – )

73. A solution containing 12.5g of non-electrolyte in 175g of water gave b.pt. elevation of 0.70 k the

molecular mass of the substance is (Kb for water = 0.52 k/kg/mol.(a) 53 (b) 106

(c) 35 (d) 72

Ans: (a) 53

Hint: M =

Δ

74. The osmotic pressure of blood is 8.21 atm at 37ºC. How much glucose should be used per

litre for an intravenous injection that is isotonic with blood

(a) 58g (b) 90g

(c) 180g (d) 5.8g

Ans: (a) 58 g

Hint: π =

75. A 4% solution of sucrose is isotonic with 3% solution of an aq. unknown substance the

molecular mass of the unknown substance will be

(a) 128 (b) 342

(c) 256 (d) 456

Ans: (c) 256

Hint:

76. Which of the following will have the same value of vant Haft’s factor (i) as that of K4[Fe(CN)6]?

(a) Al2(SO4)3 (b) Na2S2O3

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(c) Na2SO4 (d) Al(NO3)3

Ans: (a) Al2(SO4)3

Hint: Both have same number of ions formed on dissociation.

77. Assuming the salts to be completely ionised in solution which of the following has highest

osmotic pressure

(a) 1% CsCl (b) 1% RbCl

(c) 1% KCl (d) 1% NaClAns: (d) 1% NaCl

78. A solution has an osmotic pressure of 0.821 atm at 300K. Its concentration would be

(a) 0.66M (b) 0.32M

(c) 0.066M (d) 0.033M

Ans: (d) 0.033 M

Hint: π = CRT

79. Which has minimum osmotic pressure at 298 K?(a) 100 ml of IM sucrose solution (b) 200 ml of IM solution of urea

(c) Mixture of 100 ml of IM sucrose and 200 ml of IM solution of urea

(d) All are isotonic

Ans: (d) all are isotonic

80. Assertion: Two solutions of having same osmotic pressure will also have same

vapour pressures.

Reason: Lowering of vapour pressure is not a colligative property.

(a) Both assertion and reason are correct, and reason is the correct explanation of the assertion(b) Both assertion and reason are correct, but reason is not correct explanation of the assertion.



Ans: (d) Assertion is Incorrect, but reason is correct.

81. Assertion: Addition of HgI2 to aqous solution of KI shows an increase of vapour pressure

Reason: A complex K2 [HgI4] formed.





Ans: (a) If both assertion and reason are correct, and reason is the correct explanation of the

assertion

82. Assertion: There is a change in volume when acetone and chloroform mixed together to

form a solutions

Reason: The vapour pressure of the solution decreases.





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assertion

83. Osmotic pressure of blood is 7.65 atm at 310 K. An aqueous solution of glucose that will be

isotonic with blood is _________ wt/ vol.

(a) 5.41% (b) 3.54%

(c) 4.53% (d) 53.4%

Ans: (a) 5.41%

Hint:

84. The values of observed and calculated molecular weights of silver nitrate are 92.64 and170 respectively. The degree of dissociation of silver nitrate is

(a) 60% (b) 83.5%

(c) 46.7% (d) 60.23%

Ans: (b) 83.5%

Hint:

85. If α is the degree of dissociation of Na2SO4, the vant of Hoff's factor (i) used for calculating the

molecular mass is -

(a) 1 - α (b) 1 + α

(c) 1 - 2α (d) 1 + 2α

Ans: (d) 1 + 2α

Hint: α =

Here, m = 2

∴ i = 2α + 1

86. A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of 290 mm at 300 K.

The vapour pressure of propyl alcohol is 200 mm. If the mole fraction of ethyl alcohol is

0.6, its vapour pressure (in mm) at the same temperature will be

(a) 350 (b) 300

(c) 700 (d) 360

Ans: (a) 350

87. A 5.25% solution of a substance is isotonic with a 1.5% solution of urea (molar mass=60g

mol. 1) in the same solvent. If the densities of both the solutions are assumed to be equal to

1.0 gcm-3

, molar mass of the substance will be – (a) 90.0 g mol-1 (b) 115.0 g mol-1

(c) 105.0 g mol-1 (d) 210.0 g mol-1

Ans: (d) 210.0 g mol-1

Hint:

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88. At 80°C, the vapour pressure of pure liquid 'A' is 520 mm Hg and that of pure liquid 'B' is

1000 mm Hg. If a mixture solution of 'A' and 'B' boils at 80°C and 1 atm pressure, the

amount of 'A' in the mixture is (1 atm = 760 mm Hg)

(a) 52 mol % (b) 34 mol %

(c) 48 mol % (d) 50 mol %

Ans: (d) 50 mol %

89. The degree of dissociation (a) of a weak electrolyte, AxBy is related to van't Hoff factor (i)

by the expression :-

(a) α =

(b) α =

(c) α =

(d) α =

Ans: (c) α =

Hint: α =

90. A 5% solution of cane sugar (molar mass 342) is isotonic with 1% of a solution of anunknown solute. The molar mass of unknown solute in g/mol is :-

(a) 136.2 (b) 171.2

(c) 68.4 (d) 34.2

Ans: (c) 68.4

Hint:

91. From the colligative properties of solution which one is the best method for the

determination of mol. wt. of proteins & polymers :

(a) Osmotic pressure (b) Lowering in freezing point

(c) Lowering in V.F. (d) Elevation in B. Pt.

Ans: (a) Osmotic pressure

92. Pure water can be obtain from sea water

(a) Centrifugation (b) Plasmolysis

(c) Reverse osmosis (d) Sedimentation

Ans: (c) Reverse osmosis

93. A solution containing 1Og per dm3 of urea (molecular mass = 60g mol-1) is isotonic with a

5% solution of a non-volatile solute. The molecular mass of this non-volatile soluteis,[AIPMT-2006]

(a) 250g mol-1 (b) 300g mol-1 (c) 350g mol-1 (d) 200g mol-1

Ans: (b) 300g mol-1

Hint:

94. During osmosis, flow of water through a semipermeable membrane is :

(a) from both sides of semipermeable membrane with equal flow rates

(b) from both sides of semipermeable membrane with unequal flow rates

(c) from solution having lower concentration only

(d) from solution having higher concentration onlyAns: (b) from both sides of semipermeable membrane with unequal flow rates

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(81) Which one is a semi permeable membrane?

(a) Cell-wall (b) Parchment paper (c) Cello phane (d) All of these

Ans : (d)

(82) Which one is a natural semi permeable membrane?

(a) Cell wall (b) Cello phane (c) Butter paper (d) All of these

Ans : (a)

(83) Which is not a natural semi permeable membrane?

(a) Plant cellwall (b) Urinary bladder (c) Cellophane paper (d) None of theseAns : (c)

(84) Which is the best semipermeable membrane?

(a) Copper ferro cynide (b) Cell wall

(c) Parchment paper (d) None of these

Ans : (a)

(85) Which is not an artificial semipermeable membrane?

(a) Parchment paper (b) Cellophane (c) Butter paper (d) None of these

Ans : (d)

(86) Who suggested that solute in the dilute solution behaves like gas?(a) Boyl (b) Charles (c) Van't Hoff (d) Dalton

Ans : (c)

(87) Which is the correct mathematical representation of Gay-lusec's Van't Hoff law?

(a) π C (b) π V (c) π n (d) π T

Ans : (d)

(88) Which is the correct mathematical representation of Avogadro Van't Hoff law?

(a) π n (b) π C (c) π T (d) None of these

Ans : (a)

(89) Which is the correct formula to

(a)

WRMπ

TV

(b)

WRMπ

TM

Ans : (c)

(90) The solutions, which having same osmotic pressure are called which solutions?

(a) Isotonic (b) Isothermic (c) Isobaric (d) None of these

Ans : (a)

(91) Which property of isotonic solutions equal?

(a) Temperature (b) Concentration (c) Vapour pressure (d) All of these

Ans : (c)(92) In which on the following association takes place?

(a) 2BaCl

(b) R COOH (c) KCl (d) 2ZnCl

Ans : (b)

(93) What is the value of Van't Hoff factor (i) in case of association?

(a) Zero (b) Infinite (c) More than 1 (d) Less than 1

Ans : (d)

(94) When dissociation is takes place, what is the value of Van't Hoff factor (i)?

(a) more than 1 (b) less than 1 (c) 1 (d) Zero

Ans : (a)

(95) What is the value of Van't Hoff factor (i), when there is no dissociation or no association in

the solution?

(a) Less than 1 (b) 1 (c) Zero (d) None of these

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Ans : (b)

(96) How many total particles obtained on addition of 2 4 3Fe (SO )in water?

(a) 2 (b) 3 (c) 4 (d) 5

Ans : (d)3 2

2 4 3 4Fe (SO ) 2 Fe 3 SO

(97) FeCl3 gives how many particles on dissolution in water?

(a) 1 (b) 2 (c) 3 (d) 4Ans : (d)

(98) 2 4K SOgives how many particles on dissolution in water?

(a) 2 (b) 3 (c) 6 (d) 4

Ans : (b)

(100) What is the molecular weight of benzoic acid which added to kerosene?

(a) 122 (b) 61 (c) 244 (d) 209

Ans : (c)

(101) What is the value of Van't Hoff factor (i) for ideal solution?(a) 1 (b) Less than 1 (c) More than 1 (d) Zero

Ans : (a)

(102) Which of the following have Van't Hoff factor (i) equal to that of best semi permeable

membrane?

(a) 2 4 3Al (SO )

(b) HCl (c) 2 4H SO(d) 3KNO

Ans : (c)

(103) What happened in number of particles when acetic acid is dissolved in benzene?

(a) Increase (b) Decrease (c) Constant (d) Not given

Ans : (b)

(112) Which relation is true, if molecular weight of solute is x and its weight is y?

(a)

y RTx

(b)

x RTy

(c)

y RTx

(d)

y R x

T

Ans : (a)

(115) 5% sucrose solution and 0.88% (y) solutions are isotonic, what is the molecular weight of y?

(a) 19.58 (b) 59.98 (c) 98.59 (d) 55.56

Ans : (b)

WRTπ

MV

Both the solution are isotonic

W W 5 0.88

M M 342 y

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