Solutions - MCQ - One answer only

1. For a dilute solution, Raoult’s law states that:

a. the lowering of vapour pressure is equal to the mole fraction of solute
b. the relative lowering of vapour pressure is equal to the mole fraction of solute
c. the relative lowering of vapour pressure is proportional amount of solute in the solution.
d. the vapour pressure of the solution is equal to the mole fraction of solvent.
(JEE 1985)

Ans: b

Raoult’s law: The partial pressure of the vapours of a constituent is proportional to the mole fraction of the latter in the solution.

2. The pair of compounds which cannot exist together in solution is:
a. NaHCO3 and NaOH
b. Na2CO3 and NaHCO3
c. Na2CO3 and NaOH
d. NaHCO3 and NaCl
(JEE 1986)

Answer (a)

3. One molal solution is one that contains one mole of a solute in:

a. 1000 g of the solvent
b. one litre of solvent
c. one litre of the solution
d. 22.4 litres of the solution
(JEE 1986)

answer (a)