Giải thích các bước giải:

\(\begin{array}{l}
1.\\
Zn + 2HCl \to ZnC{l_2} + {H_2}\\
{n_{Zn}} = 0,2mol\\
a)\\
{n_{{H_2}}} = {n_{Zn}} = 0,2mol\\
 \to {V_{{H_2}}} = 4,48l\\
b)\\
{n_{HCl}} = 2{n_{Zn}} = 0,4mol\\
 \to {m_{HCl}} = 14,6g\\
 \to {m_{{\rm{dd}}HCl}} = \dfrac{{14,6}}{{25\% }} \times 100\%  = 58,4g\\
c)\\
{n_{ZnC{l_2}}} = {n_{Zn}} = 0,2mol \to {m_{ZnC{l_2}}} = 27,2g\\
 \to {m_{{\rm{dd}}}} = {m_{Zn}} + {m_{{\rm{dd}}HCl}} - {m_{{H_2}}} = 71g\\
 \to C{\% _{ZnC{l_2}}} = \dfrac{{27,2}}{{71}} \times 100\%  = 38,3\% \\
2.\\
CaO + 2HN{O_3} \to Ca{(N{O_3})_2} + {H_2}O\\
{n_{CaO}} = 0,15mol\\
a)\\
{n_{Ca{{(N{O_3})}_2}}} = {n_{CaO}} = 0,15mol\\
 \to {m_{Ca{{(N{O_3})}_2}}} = 24,6g\\
b)\\
{n_{HN{O_3}}} = 2{n_{CaO}} = 0,3mol \to {m_{HN{O_3}}} = 18,9g\\
 \to C{\% _{HN{O_3}}} = \dfrac{{18,9}}{{250}} \times 100\%  = 7,56\% \\
c)\\
{m_{{\rm{dd}}muoi}} = {m_{CaO}} + {m_{HN{O_3}}} = 258,4g\\
 \to C{\% _{Ca{{(N{O_3})}_2}}} = \dfrac{{24,6}}{{258,4}} \times 100\%  = 9,52\% \\
3.\\
Ca{(OH)_2} + {H_2}S{O_4} \to C{\rm{aS}}{O_4} + 2{H_2}O\\
{n_{Ca{{(OH)}_2}}} = 0,24mol\\
a)\\
{n_{{\rm{CaS}}{O_4}}} = {n_{Ca{{(OH)}_2}}} = 0,24mol\\
 \to {m_{{\rm{CaS}}{O_4}}} = 32,64g\\
b)\\
{n_{{H_2}S{O_4}}} = {n_{Ca{{(OH)}_2}}} = 0,24mol\\
 \to {m_{{H_2}S{O_4}}} = 23,52g\\
 \to {m_{{\rm{dd}}{H_2}S{O_4}}} = \dfrac{{23,52}}{{30\% }} \times 100\%  = 78,4g
\end{array}\)