At $300 \mathrm{K}$, a sample of $3.0 \mathrm{g}$ of gas A occupies the same volume as $0.2 \mathrm{g}$ of hydrogen at $200 \mathrm{K}$ at the same pressure. The molar mass of gas $\mathrm{A}$ is ${\mathrm{mol}}^{-1}$ (nearest integer) Assume that the behaviour of gases as ideal. (Given: The molar mass of hydrogen $\left({\mathrm{H}}_2\right)$ gas is $\left.2.0 \mathrm{g}{ \mathrm{mol}}^{-1}\right)$