Question

Why is air called a mixture? Give five facts in support of your answer.

Answer 1

When two substances are mixed together in any proportion, they do not undergo any chemical change but retain their proportions.

Air is a mixture because:

1. Air cannot be represented by a formula, as its constituents are not fixed in proportion. a compound is always represented by a formula.
2. The component of air retain their individual properties but in the compound, the individual properties of the components are not evident.
3. When air is formed out of its constituents no change in mass and no change in volume takes place.
4. Properties of air vary from place to place and from time to time. As at different places, different amounts of gases are present in the air.
5. Air can be separated into its constituents such as oxygen, nitrogen, etc. by physical methods but compounds cannot be separated by physical methods.