Giải thích các bước giải:
\(\begin{array}{l}
2C{H_3}{\rm{COOH + Mg}} \to {(C{H_3}{\rm{COO}})_2}Mg + {H_2}\\
{n_{Mg}} = 0,1mol \to {n_{C{H_3}{\rm{COOH}}}} = 2{n_{Mg}} = 0,2mol\\
\to {n_{{H_2}}} = {n_{Mg}} = 0,1mol\\
\to C\% C{H_3}{\rm{COOH = }}\dfrac{{0,2 \times 60}}{{200}} \times 100\% = 6\% \\
{V_{{H_2}}} = 2,24l\\
{m_{{\rm{dd}}}} = {m_{Mg}} + {m_{C{H_3}{\rm{COOHdd}}}} - {m_{{H_2}}} = 202,2g\\
{n_{{{(C{H_3}{\rm{COO}})}_2}Mg}} = {n_{Mg}} = 0,1mol\\
\to C\% {(C{H_3}{\rm{COO}})_2}Mg = \dfrac{{0,1 \times 142}}{{202,2}} \times 100\% = 7,02\%
\end{array}\)