Question

Clean air is a _________ mixture.

Answer 1

Clean air is a homogeneous mixture because:

• Clean air consists of only gaseous components like various gases namely Hydrogen $\left({\mathrm{H}}_2\right)$, Nitrogen $\left({\mathrm{N}}_2\right)$, Oxygen $\left({\mathrm{O}}_2\right)$, water vapours etc.
• As a result all the gaseous phase constituents intermix with each other to create uniformity in the composition of air throughout.
• There is no clear boundary of separation in the the clean air.

Note: Air comprising of gases, dust particles and microbes will be a heterogeneous mixture.

Mixture: When two or more substances are mixed in any proportion.

• The components of a mixture can be separated by physical methods of separation.
• Example: A mixture of Sand and Iron $\left(\mathrm{Fe}\right)$ can be separated by the use of a magnet.

Homogeneous mixture: Any substance containing more than one type of constituent particles and exhibits uniformity in its composition and properties throughout its mass is known as a homogeneous mixture.

• Example: A solution of salt and water, tea, clean air etc.

Heterogeneous mixture: Any substance that does not exhibit uniformity in its composition and properties throughout its mass is known as a heterogeneous matter.

• Example: Muddy water, milk, blood, air

Therefore, clean air is a homogeneous mixture.