Question

Which of the following is not a pure substance?
a. Common salt
b. Sugar
c. Rain water
d. Iron

Answer 1

rain water because it the substance that is extracted from cloud and cloud is made of dust particles

Answer 2

Common salt, iron and sugar are pure substances but rainwater is not.

Rain water consists of several gases like carbon dioxide, oxygen, oxides of nitrogen, and sulphur.

Sometimes the rain water also contains dust particles.

Gases makes the rain water acidic.

A pure substance is one that cannot be separated by any physical or chemical processes.

Elements are the example of pure substances.