Question

Why air is not always regarded as homogeneous mixture?

Answer 1

air is not always a homogeneous mixture as its different parts can contain different gases in different amount for example place full of industries will have large amount of smoke as compared to other areas

Answer 2

Air contains various gases in specific proportions, primarily consisting of nitrogen and oxygen and thereby forms a homogenous mixture. However, instances of air pollution have an impact on its composition and it can no longer be called a homogenous mixture.

Heavy forestation, volcanic activity as well as industrial pollution results in alteration of the composition of air and makes it a heterogeneous mixture.