A buffer is produced by mixing 20.0 $cm^3$ of 0.10 $mol \ dm^{−3}$ ethanoic acid, $CH_3COOH(aq)$, with 0.10 $mol dm^{−3}$ sodium hydroxide, $NaOH(aq)$.

A buffer is produced by mixing 20.0 $cm^3$ of 0.10 $mol \ dm^{−3}$ ethanoic acid, $CH_3COOH(aq)$, with 0.10 $mol dm^{−3}$ sodium hydroxide, $NaOH(aq)$.

What is the volume of $NaOH$ required and the pH of the buffer?

$$\begin{array}{|c|c|c|} \hline \text{Answer}&\text { Volume of } \mathrm{NaOH} / \mathrm{cm}^3 & \text { pH of buffer } \\ \hline A&40.0 & 9.2 \\ \hline B&40.0 & 4.8 \\ \hline C&10.0 & 9.2 \\ \hline D&10.0 & 4.8 \\ \hline \end{array}$$