$\begin{aligned} & \mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH}+\mathrm{NaHCO}_3 \rightarrow \mathrm{C}_6 \mathrm{H}_5 \mathrm{COO} \mathrm{Na}^{+} \\ & +\mathrm{H}_2 \mathrm{O}+\mathrm{CO}_2\end{aligned}$

$$\begin{aligned} & \mathrm{x} \mathrm{~gm} \quad \text{11.2 L}\\ & \text { mole of } \mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH}=\text { mole of } \mathrm{CO}_2=\frac{11.2}{22.4}=0.5 \\ & \text { mass of } \mathrm{C}_6 \mathrm{H}_5 \mathrm{COOH}=\mathrm{x}=0.5 \times 122=61 \mathrm{gm} \end{aligned}$$