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