Chemistry - Ionic Equilibrium Question with Solution | TestHub

$\left[{\mathrm{CH}}_3\mathrm{COOH}\right]=\text{ millimoles of }{\mathrm{CH}}_3\mathrm{COOH}$ $=0.1\times 10=1.0$ $\begin{array}{l}\left[{\mathrm{CH}}_3\mathrm{COONa}\right]=\text{ millimoles of }{\mathrm{CH}}_3\mathrm{COONa}\\ =0.1\times 20=2.0\end{array}$ From, Henderson Hasselbalch equation, $\begin{array}{l}\mathrm{pH}={\mathrm{pK}}_{\mathrm{a}}+\log \frac{\text{ [conjugate base] }}{[\text{ acid }]}\\ =4.74+\log \frac{2}{1}=4.74+0.30=5.04\end{array}$