When a Substance Is Impure?

An impure substance is a type of mixture, so melting points can be used to find out if a substance is pure or impure. Impure substances tend to have a slightly lower melting point than the pure substance, and a broader melting temperature range.

What is an impure substance called?

Impure substances are made up of different kinds of elements combined together or more pure substances mixed together in any proportion. Impure substances are also called mixtures.

What happens when a substance contains an impurity?

It is difficult to get completely pure substances – there will almost always be other substances mixed in. Even the most pure water will contain dissolved gases from the air. Impurities in a substance will affect its properties. For example, they may change its boiling point.