Em tham khảo nha:

\(\begin{array}{l}
1)\\
a)\\
MgO + 2HCl \to MgC{l_2} + {H_2}O\\
MgC{O_3} + 2HCl \to MgC{l_2} + C{O_2} + {H_2}O\\
b)\\
{n_{C{O_2}}} = \dfrac{{0,336}}{{22,4}} = 0,015\,mol\\
{n_{MgC{O_3}}} = {n_{C{O_2}}} = 0,015\,mol\\
\% {m_{MgC{O_3}}} = \dfrac{{0,015 \times 84}}{{2,06}} \times 100\%  = 61,17\% \\
\% {m_{MgO}} = 100 - 61,17 = 38,83\% \\
2)\\
2Al + 6HCl \to 2AlC{l_3} + 3{H_2}\\
{n_{{H_2}}} = \dfrac{{11,2}}{{22,4}} = 0,5\,mol\\
{n_{Al}} = \dfrac{{0,5 \times 2}}{3} = \frac{1}{3}\,mol\\
{m_{hh}} = \dfrac{1}{3} \times 27 + 12,8 = 21,8g\\
\% {m_{Al}} = \dfrac{{\frac{1}{3} \times 27}}{{21,8}} \times 100\%  = 41,28\% \\
\% {m_{Cu}} = 100 - 41,28 = 58,72\% 
\end{array}\)