The mass of $11.2\text{liters}$ of a certain gas at STP is $24\text{g}$. Find the gram molecular mass of the gas.

Step 1: Given information

The mass of $11.2\text{liters}$ of a certain gas at STP is $24\text{g}$.

Step 2: S.T.P

• S.T.P indicates standard temperature and pressure.
• At S.T.P, one mole of a gas has a volume of $22.4\text{L}$.
• The mass of $22.4\text{L}$ of a gas is equal to its gram molecular mass.

Step 3: Calculation of gram molecular mass

$\text{11.2 L}$ of the gas at STP weighs $24\text{g}$

$22.4\text{L}$ of the gas at STP weighs $\frac{24}{11.2}\times 22.4\text{=48 g}$

Hence, the gram molecular mass of the gas is $48\text{g}$.