Question

A gaseous mixture contains oxygen and nitrogen in ratio 1:4 by weight. The ratio of their number of molecules is?

Answer 1

Given, $\frac{Oxygen}{Nitrogen}=\frac{1}{4}$ (by weight)

Molecular weight of oxygen

$=2\times 16=32$

Molecular weight of nitrogen

$=2\times 14=28$

Ratio of number of molecules

$=\frac{1}{4}\times \frac{28}{32}=\frac{7}{32}$