Question

Which one of the following solutions will have
higher vapour pressure than that of water
(a) aqueous solution of CH OH
(b).
aqueous solution of H2SO.
(c) aqueous solution of sugar
(d) aqueous solution of urea

Answer 1

Explanation:

1 molal NaCl

One molar (1M) aqueous solution is more concentrated than one molal aqueous solution of the same solute.

In solution, H

2

SO

4

provides three ions, while NaCl provides two ions. Hence, the vapour pressure of a solution of NaCl is higher (as it gives less number of ions).

Therefore, 1 molal NaCl will have the maximum vapour pressure.