Concept of vapor pressure

Question

The vapor pressure of a liquid increases linearly with increasing temperature?

(a) True

(b) False

(c) Can't say

(d) None

Solution

Vapor pressure increases non-linearly according to the Clausius- Clapeyron Equation.

!!rArr!! !! lnP = lnC - (DeltaH_(vap))/(RT)!!

And !! ln(P_2/P_1) = ((DeltaH_(vap))/R)(1/T_1-1/T_2)!!

!!P_2!! is the vapour pressure at temperature !!T_2!!

!!P_1!! is the vapour pressure at temperature !!T_1!!

Therefore option (b) is correct.