Question bank for unit: Solutions:

Multiple choice questions(CUET):

1. Equimolar solutions in the same solvent have:
A. Same elevation in boiling point and same depression in freezing
point
B.Different elevation in boiling point and different depression in
freezing point
C.Same elevation in boiling point but different depression freezing
point
D.Same depression in freezing point but different elevation in boiling
point

2. Sprinkling of salt helps in clearing the snow-covered roads in hills.

The
phenomenon involved in the process is
A. Lowering in vapor pressure of snow
B. Depression in freezing point of snow

C. Increase in freezing point of snow

D. Melting of ice due to increase in temperature by putting salt

3. The relative lowering in vapor pressure is proportional to the ratio of

number of:

A. Solute molecules to solvent molecules

B.Solvent molecules of solute molecules

C.Solute molecules to the total number of molecules in solution

D.Solvent molecules to the total number of molecules in solution

4. Which of the following statements is correct?

A. A saturated solution will remain saturated at all temperatures

B.A plant cell swells when placed in hypertonic solution

C.The depression in freezing point is directly proportional to

molality of the solution

D. Lowering in vapor pressure is a colligative property

5. A plant cell shrinks when it is kept in a

A.Hypotonic solution

B. Hypertonic solution

C. Isotonic solution

D. Pure water

6. Which of the following statements is not correct?

A. 5% aqueous solutions of A NaCl and KCI are said to be isomolar

B. 1 M sucrose solution and 1 M glucose solution are isotonic

C. Molecular mass of acetic acid and benzoic acid is higher than normal
mass in

cryoscopic methods

D. For the same solution, ΔΤЬ /ΔΤ = Kb/Kf

7. A solution is made by dissolving 20g of a substance in 500mL of water. Its

osmotic

pressure was found to be 600mm of Hg at 15°C. Find the molecular weight

of the

substance.

A.1198

B. 500
 C. 1200

D. 1000

8. Osmotic pressure of a solution containing 2g dissolved protein per 300cm²

of solution

is 20mm of Hg at 27° C. The molecular mass of protein is

A. 6239.6 g mol-1

B.12315.5 g mol-1

C. 3692.1 g mol-1

D. 7368.4 g mol-1

9. What will be the osmotic pressure in Pascal’s exerted by a solution

prepared by

dissolving 1.0 g of polymer of molar mass 150,000 in 500 mL of water at

37°C?

A. 30.96 Pa

B. 34.36 Pa

C. 68.72 Pa

D. 48.25 Pa

10. A solution containing 10.2g glycerine per litre is isotonic with a 2%

solution of

glucose. What is the molecular mass of glycerine?

A. 91.8 g

B. 1198 g

C. 83.9 g

D. 890.3 g

11. 10% solution of urea is isotonic with 6% solution of a volatile solute

X.What is the
 molecular mass of solute X?

A. 6 g mol-1

B. 60 g mol-1

C. 36 g mol-1

D. 32 g mol-1

12. Which of the following statements is not correct?

A. Osmotic pressure (π) of a solution is given by the relation π= MRT,

where M is

the molarity of the solution

B.The correct order of osmotic pressure for 0.2M aqueous

solution of each solute is CaCl2 >NaCl > CH3 COOH > glucose

C. Two solutions of sucrose of same molality prepared in

different solvents will have same elevation in boiling point

D. Relative lowering in vapour pressure of a solution containing

non-volatile solute is directly proportional to mole fraction of

solution is Raoult 's law

13. The preservation of meat by salting and of fruits by adding sugar

protects them from

bacterial action because:

A. Bacteria die of eating sugar or salt

B. Due to osmosis bacteria lose water on salted meat or candid fruit and
die
C. Due to osmosis bacteria gain water on salted meat or candid fruit and
die

D.Bacteria get stuck to the salt and sugar layers and die
14. What weight of glycerol should be added to 600g of water in order to
lower its

freezing point by 10°C? (Kf = 1.86° Cm¯¹)

A. 496 g

B. 297 g

C. 310 g

D. 426 g

15. Which of the two has lower freezing point, 2m NaCl or 5m NaCl aqueous
solution?

A.2m NaCl solution

B. Both have same freezing point

C. 5m NaCl solution

D. The solutions cannot freeze

16. The molal elevation constant is the ratio of the elevation in B.P. to:

A. Molality

B.Mole Fraction of solute

C. Molarity

D. Mole fraction of solvent

17. Beckmann thermometers are used to measure:

A. Boiling point of solution

B. Elevation in boiling point or B depression in freezing point
C. Any temperature
D. Freezing point of solution
18. Which of the following is a colligative property?

A. Molality

B. Viscosity

C. Relative lowering of vapour pressure

D. Surface tension

19. What is the boiling point of a 3 molal aqueous solution if Kb is 0.512

°C/m?

A. 101 K

B.101.536 °C

C. 90.536 °C

D. 0K

(CBSE) CASE BASE STUDY QUESTIONS:

4 marks

1. Binary solutions can be of nine different types depending upon the nature
of the

solute and solvent whether solid, liquid or gas. They may be further
classified as

solid, liquid and gaseous solutions based on the component which acts as
the solvent. However, the liquid solutions are the most important. Both
solids and gases dissolve in liquids resulting in homogeneous mixtures, i.e.
solutions. The solubility is governed by a number of factors such as nature of
solute and solvent, temperature, pressure etc. The concentrations of the
solutions can be expressed in different ways such as normality, molarity,
molality, mole fraction etc. Out of these, molality and mole fraction are
better as they do not change with the change in temperature.

Read the given passage carefully and give the answer of the following
questions

Q1. Solubility curve of Na2SO4-10H20 in water with temperature is given as:

a. solubility process is exothermic

b. solubility process is exothermic till 34°C and endothermic after 34°C

c. solubility process is endothermic till 34°C and exothermic after -34°C

d. solubility process is endothermic

Q2. CuSO4.5H₂O is a:

a. solution of solid in a liquid

b. solution of liquid in a solid

c. salt only and cannot be called a solution

d. coordination compound of copper with water molecules as the ligands

Q3. The molality of a sulphuric acid solution in which mole fraction of water
is 0.85 is:

a. 9.80

b. 10.58

c. 10.50
 d. 11.25

Q4. Maximum amount of a solid solute that can be dissolved in a specified

amount of a

given liquid solvent does not depend upon:

a. temperature

b. pressure

c. nature of solute

d. nature of solvent

Given questions are of 2 marks each :

2.Give an example of a material used for making a semipermeable

membrane for

carrying out reverse osmosis.

3. What is a "semi-permeable membrane"?

4.. Why is the vapour pressure of an aqueous solution of glucose lower than
that of

water?

Given questions are of 3 marks each :

5. (a) Explain the following phenomena with the help of Henry's law.

(i) Painful condition known as bends.

(ii) Feeling of weakness and discomfort in breathing at high altitude.

(b) Why does a soda water bottle kept at room temperature fizz on
opening?

6. Why are aquatic species more comfortable in cold water in comparison to

warm

water?

7. What is the significance of Henry's Law constant KH?

8. Concentration terms such as mass percentage, ppm, mole fraction and

molality are
 independent of temperature, however molarity is a function of
temperature. Explain.

9. Explain the solubility rule "like dissolves like" in terms of intermolecular

forces that

exist in solutions.

10. Define cryoscopic constant (molal freezing point depression constant.)

Given questions are of 5 marks each :

11. Under what condition molality and molarity of a solution are identical.
Explain with suitable reasons.

12.Derive expression for Raoult’s law when the solute is non-volatile.

Given questions are of 1 mark each :

• Directions: These questions consist of two statements, each

printed as

Assertion and Reason. While answering these questions, you are

required to

choose any one of the following four responses.

(a) If both Assertion and Reason are correct and the Reason is a correct
explanation of the Assertion.

(b) If both Assertion and Reason are correct but Reason is not a correct
explanation of the Assertion.

(c) If the Assertion is correct but Reason is incorrect.

(d) If both the Assertion and Reason are incorrect.

13. Assertion: When methyl alcohol is added to water, boiling point of water
increases.

Reason: When a volatile solute is added to a volatile solvent elevation in

boiling point
 is observed.

14. Assertion: When NaCl is added to water a depression in freezing point is

observed.

Reason: The lowering of vapour pressure of a solution causes

depression in the

freezing point.

15. Assertion : Azeotropic mixtures are formed only by non-ideal solutions

and they

may have boiling points either greater than both the

components or less

than both the components.

Reason: The composition of the vapour phase is same as that of the

liquid phase of

an azeotropic mixture.