Solutions (Questions)

A.    Very-Short-Answer Questions

1.      What is a solution?

2.      In a mixture of ethanol and water, their mole fractions are 0.25 and 0.75 respectively. Which is the solvent?

3.      Give an example of solution of gas in solid.

4.      Is the dissolution of gases in water endothermic or exothermic?

5.      What is the effect of temperature on the solubility of gases?

6.      What are units of the molal elevation constant?

7.      A 0.1 M solution of urea is isotonic with a glucose solution. What is the molarity of the glucose solution?

8.      What is the van’t Hoff factor for urea in an aqueous solution?

9.      What is the expected value of the van’t Hoff factor for FeSO₄ ?

10.  What is the van’t Hoff for acetic acid in benzene?

B.    Short-Answer Questions

1.      Why are most gases sparingly soluble in water?

2.      Why are NH₃  and HCI the most soluble gases in water?

3.      What is Henry’s law for the solubility of gases?

4.      Why does the solubility of gas in water decrease on heating?

5.      Why is alcohol miscible with water in all proportion?

6.      Why are solids with high molecular weights less soluble?

7.      Why is an ionic solid insoluble in a nonpolar solvent?

8.      What is difference between the formality and molarity of acetic acid in an aqueous solution?

9.      What is the sum of the mole fractions of all the components of a solution?

10.  What is an ideal solution?

11.  What is Raoult’s law for the vapour pressure of a mixture of two volatile liquids?

12.  What is the relative lowering of vapour pressure of a solvent?

13.  When does a liquid boil?

14.  Why is the boiling point of a solution of a nonvolatile solute higher than that of the pure solvent?

15.  What is a constant boiling mixture?

16.  What do you understand by depression of the freezing point?

17.  What is a colligative property?

18.  Why is the vapour pressure of a solution less than of the solvent?

19.  Give any five example of ideal solutions.

20.  How is freezing of a solution different from the freezing of a pure solvent?

21.  What is an antifreeze?

22.  What is a semipermeable membrane?

23.  What is osmosis?

24.  What is osmotic pressure?

25.  A 5% (w/w) solution of urea is isotonic with a 5%(w/w) solution of a compound A. What is the molar mass of A?

26.  Why is the measurement of osmotic pressure suitable for the determination of the molar mass of a polymer?

27.  What is the van’t Hoff factor ?

28.  What is reverse osmosis?

29.  Why is the ebullioscopic constant of a liquid generally smaller than its cryoscopic constant?

C.    Long-Answer Questions

1.      Discuss the factor that affect the dissolution of a solute in a solvent.

2.      Explain why ethanol and water cannot be separated completely by fractional distillation.