Freezing point depression worksheet





When the freezing point of a liquid is lowered down by using another compound, Freezing point depression occurs.

The solution has the lower freezing point.For example, the freezing point of seawater is lower than that of pure water.

Here, you can find some questions related to Freezing point depression and their answers:

Questions:

1. Find the volume of a solution having 1 mol of sugar and an osmotic pressure of 1 atm at O^0C:

(a)    11.2 litre

(b)   2.24 litre

(c)    22.4 litre

(d)   112 litre

 

2. The osmotic pressure of 0.2 molar solution of urea at 27^0C is (R = 0.082 litre atm ml^{-1} K^{-1}) is:

(a)    4.92 atm

(b)   27 atm

(c)    0.2 atm

(d)   1 atm

 

3. The value of ebullioscopic constant depends upon:

(a)    nature of solute

(b)   nature of solvent

(c)    \Delta H solution

(d)   freezing point of solution

 

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

(a)    molality

(b)   molarity

(c)    normality

(d)   mole fraction of solvent

 

5. The elevativity in boiling point of 0.1 M solutions of urea, glucose and NaCl will be:

(a)    in the ratio 1 : 3 : 1

(b)   in the ratio 1 : 1 : 2

(c)    in the ratio 1 : 3 : 2

(d)   none of these

 

6. The rise in the boiling point of a solution containing 1.8 g of glucose in 100 g of solvent is 0.1^0C. The molal elevation constant of the liquid is:

(a)    1 K/m

(b)   0.1 K/m

(c)    0.01 K/m

(d)   10 K/m

 

7. The freezing point of 0.1 M solution of glucose is -1.86^0 C If an equal volume of 0.3 M glucose solution is added, the freezing point of the mixture will be:

(a)    -5.58^0C

(b)   -7.44^0 C

(c)    -3.72^0C

(d)   -2.79^0C

 

8. The boiling point of a solution of 0.11 g of a substance in 15 g of ether was found to be 0.1^0C higher than that of pure ether. The molecular weight of the substance will be (K_b = 2.16)

(a)    168

(b)   158

(c)    148

(d)   178

 

9. 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 1.86^0C per mole, the mixture shall freeze at:

(a)    -1.86^0C

(b)   -0.93^0C

(c)    0.93^0C

(d)   1.86^0C

 

10. Which of the following is correctly matched?

Solvent                                         Ebullioscopic constant

(a) benzene                                              2.53

(b) acetone                                              0.51

(c) water                                                  1.86

(d) chloroform                                        1.22

 

11. The depression of freezing point is directly proportional to:

(a)    molarity of the solution

(b)    mole fraction of the solution

(c)    molality of the solution

(d)   molarity of the solvent

 

12. A solution of 1 molal concentration of a solute will have maximum boiling point elevation when the solvent is:

(a)    acetone

(b)   ethyl

(c)    benzene

(d)   chloroform

Answers:

1.(c)     2. (a)     3. (b)     4. (a)     5. (b)

6. (a)     7. (c)     8. (b)     9. (b)     10. (a)

11. (c)     12. (c)



Related posts:

  1. Depression of freezing point We know that a liquid freezes only when its vapour...
  2. Elevation of boiling point Elevation of boiling point It is known that a liquid...
  3. Types of Solutions The solutions may be classified on the basis of solubility....
  4. Woorksheet on Osmotic pressure The pressure which is applied to a solution to prevent...
  5. Osmotic pressure It is the flow of solvent molecules from the solvent...