Question

With reference to the stated properties give reasons why air is considered a mixture and not a compound.

Answer 1

1. Variable Composition:

   • Air is a mixture of gases like nitrogen (78%), oxygen (21%), and traces of other gases.
   • The proportion of these gases can vary (e.g., humidity levels can change due to water vapor).

2. No Chemical Bonding:

   • The gases in air are not chemically bonded to each other; they are physically combined.

3. Separation:

   • Components of air (e.g., oxygen, nitrogen, argon) can be separated by physical methods like fractional distillation.

4. Retained Properties:

   • Each gas in air retains its individual properties. For example:
     1. Oxygen supports combustion.
     2. Carbon dioxide is used in photosynthesis.