Question

What is the mass of $\text{0.5}$ moles of ozone molecules?

• A. $8\text{g}$
• B. $16\text{g}$
• C. $24\text{g}$
• D. $48\mathrm{g}$

Answer 1

The correct option is C

$24\text{g}$

Explanation:

Given:

Moles of ozone$\left({\mathrm{O}}_3\right)$ $=0.5\mathrm{mol}$

Step 1. Formula for number of moles:

$\text{Number of moles}=\frac{\text{Mass}}{\text{Molar mass}}$-----------------------(I)

Step 2. Calculation of molar mass of ozone molecule$\left({\mathrm{O}}_3\right)$:

Molar mass of ozone molecule =$3\times \text{atomic mass of oxygen}$

=$\left(3\times 16\right)\mathrm{g}{\mathrm{mol}}^{-1}$$=$ $48\mathrm{g}{\mathrm{mol}}^{-1}$

Step 3. Calculation of mass of ozone molecule:

Substituting the values in equation (I), we get

$$\begin{gathered} 0.5\text{mol}=\frac{\text{Mass}}{48{\text{g mol}}^{-1}} \\ \text{Mass = 48}\mathrm{g}{\mathrm{mol}}^{-1}\text{×0.5 mol}=24\text{g} \end{gathered}$$

Thus, the mass of $\text{0.5}$ moles of ozone molecules is $24\text{g}$.

Hence, the correct option is (C).