Question

The density of an ideal gas at STP is $1.20g{L}^{-1}$. The molecular mass of the gas is ____ $gmo{l}^{-1}$.

Answer 1

Answer: 26.90

$d=\frac{PM}{RT}$
$M=\frac{dRT}{P}$
$=\frac{1.20\times 0.0821\times 273}{1}$
$=26.90gmo{l}^{-1}$