Question

Why is air is considered As a mixture whereas salt as a pure substance?

Answer 1

Answer:

A pure substance is either an element (e.g. carbon, oxygen, nitrogen, sodium, lead etc.) or a compound (e.g. H2O, CO2, NH3, NaCl etc.). Air comprises elements such as N2, O2, argon and also compounds such as CO2, H2O(water vapour) etc. Hence, air is a mixture and not a pure substance.

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