Question

What is classified as a pure substance

Answer 1

A pure substance has a definite and constant composition — like salt or sugar. A pure substance can be either an element or a compound, but the composition of a pure substance doesn't vary.

Answer 2

A substance with precise melting and freezing point.

Step-by-step explanation:

A pure substance is one that has a precise melting and freezing point

Like water, pure water boils at 100C while impure water will boil at a temperature less than that.

Impurity also affects the refractive index and specific gravity of a substance