Question

Positive deviation showing from Raoult’s law is?

(a) Water – hydrochloric acid

(b) Acetone – chloroform

(c) Water – nitric acid

(d) Benzene – methanol

The question was asked in a national level competition.

The question is from Two component Gas -Two component Liquid system-II topic in chapter Multiphase Equilibrium of Chemical Process Calculation

Answer 1

Correct answer is (b) Acetone – chloroform

To elaborate: Benzene – methanol mixture the intermolecular forces of attractions are weaker than those in pure liquids. Hence this mixture shows positive deviation.