Question

A substance which decomposes at or below its boiling point cannot be purified by?

• A. Steam distillation
• B. Simple distillation
• C. Fractional distillation
• D. Distillation under reduced pressure

Answer 1

Answer: (A), (B), (C)

The correct options are
A Steam distillation
B Simple distillation
C Fractional distillation

Steam distillation is used for natural aromatic compounds which are immiscible in water.

Simple and fractional distillation uses the property of difference in the boiling point. These techniques can not be used for the substance which decomposes at or below its boiling point.
Distillation under reduced pressure is basically Vaccum distillation. This method is used to boil such substances without their decomposition
Option A, B and C are the answer.