12.C

13.B

14.C

15.C

Em tham khảo nha :

\(\begin{array}{l}
12)\\
C\\
Fe + 2HCl \to FeC{l_2} + {H_2}\\
{n_{Fe}} = \dfrac{{11,2}}{{56}} = 0,2mol\\
{n_{{H_2}}} = {n_{Fe}} = 0,2mol\\
{V_{{H_2}}} = 0,2 \times 22,4 = 4,48l\\
13)\\
B\\
2Al + 3{H_2}S{O_4} \to A{l_2}{(S{O_4})_3} + 3{H_2}\\
{n_{{H_2}}} = \dfrac{{6,72}}{{22,4}} = 0,3mol\\
{n_{Al}} = \dfrac{2}{3}{n_{{H_2}}} = 0,2mol\\
{m_{Al}} = 0,2 \times 27 = 5,4g\\
14)\\
C\\
Zn + {H_2}S{O_4} \to ZnS{O_4} + {H_2}\\
Fe + {H_2}S{O_4} \to FeS{O_4} + {H_2}\\
2Al + 3{H_2}S{O_4} \to A{l_2}{(S{O_4})_3} + 3{H_2}\\
15)\\
C\\
CuO + 2HCl \to CuC{l_2} + {H_2}O\\
N{a_2}O + 2HCl \to 2NaCl + {H_2}O\\
CaO + 2HCl \to CaC{l_2} + {H_2}O
\end{array}\)