Đáp án:
a)
\(\begin{array}{l}
{m_{Zn}} = 13g\\
{m_{ZnO}} = 8,1g
\end{array}\)
b)
\({m_{HCl}} = 300g\)
Giải thích các bước giải:
a)
\(\begin{array}{l}
Zn + 2HCl \to ZnC{l_2} + {H_2}(1)\\
ZnO + 2HCl \to ZnC{l_2} + {H_2}O(2)\\
{n_{{H_2}}} = \dfrac{V}{{22,4}} = \dfrac{{4,48}}{{22,4}} = 0,2mol\\
{n_{Zn}} = {n_{{H_2}}} = 0,2mol\\
{m_{Zn}} = n \times M = 0,2 \times 65 = 13g\\
{m_{ZnO}} = {m_{hh}} - {m_{Zn}} = 21,1 - 13 = 8,1g\\
b)\\
{n_{ZnO}} = \dfrac{m}{M} = \dfrac{{8,1}}{{81}} = 0,1mol\\
{n_{HCl(1)}} = 2{n_{Zn}} = 2 \times 0,2 = 0,4mol\\
{n_{HCl(2)}} = 2{n_{ZnO}} = 2 \times 0,1 = 0,2mol\\
{n_{HCl}} = {n_{HCl(1)}} + {n_{HCl(2)}} = 0,4 + 0,2 = 0,6mol\\
{m_{HCl}} = n \times M = 0,6 \times 36,5 = 21,9g\\
{m_{HCl}\text{cần dùng}} = \dfrac{{{m_{HCl}} \times 100}}{{7,3}} = 300g
\end{array}\)
