Derivation of Konowaloff's Rule from Duhem Margules equation
According to Duhem Margules equation,
If P is the total pressure then-
P = p1 + p2
dP = dp1 + dp2
This means that the vapour is richer in component 1 (or A) than is the liquid from which is vaporises.
Source: Chemistry for Degree Students By R. L. MADAN