$\begin{array}{l}
{n_{C{H_3}COOH}} = 0,1V\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{n_{C{H_3}COONa}} = 0,01\\
\\
+ C{H_3}COONa \to C{H_3}CO{O^ - } + N{a^ + }\\
0,01...........................0,01\\
\\
\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}COOH \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over
{\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} C{H_3}CO{O^ - }\,\,\,\,\,\, + {H^ + }\\
Ban\,dau\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0,1V\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0,01\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0\\
Phan\,ung\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\\
Con\,lai\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0,1V - x\,\,\,\,\,\,\,\,\,\,\,\,\,0,01 + x\,\,\,\,\,\,\,\,\,\,\,\,\,x\\
\\
PH = 4,7 \to \left[ {{H^ + }} \right] = {1,82.10^{ - 5}}\\
\left\{ \begin{array}{l}
\frac{x}{{V + 0,1}} = {1,82.10^{ - 5}}\\
\frac{{x\left( {0,01 + x} \right)}}{{0,1V - x}} = {K_a} = {1,8.10^{ - 4}}
\end{array} \right.
\end{array}$