Question

(a) prove
م
pressure is a
that relative lowering in vapour
colligative property?
sepraphical Representation of elevation in
Stiling point.
(a) Alcording to Raults lovo​

Answer 1

Explanation:

Let us assume a binary solution in which the mole fraction of the solvent be x1 and that of the solute be x2, p1 be the vapour pressure of the solvent and p1o be the vapour pressure of the solvent in pure state.

According to Raoult’s Law:

p1=x1p1o…………………………..(1)

The decrease in vapour pressure of the solvent (∆p1) is given by:

=> ∆p1=p1o-p1

=> ∆p1=p1o-p1ox1 [using equation (1)]

=> ∆p1=p1o (1-x1)

Since we have assumed the solution to be binary solution, x2=1-x1

=> ∆p1=p1ox2

=> x2= ∆p1/p1o