Question

Which of the following mixtures can be separated by fractional distillation?
I) Iron filings and sand
II) Nitrogen and oxygen
III) Sawdust and stones

Answer 1

Fractional distillation is used to separate components of a mixture containing miscible liquids having lower boiling point difference.
Fractional distillation can also be used to separate components of air. For that, air is first liquefied by increasing pressure and decreasing temperature. Therefore, mixture of nitrogen and oxygen can be separated by fractional distillation.