Em tham khảo nha:

\(\begin{array}{l}
7)\\
a)\\
2Zn + {O_2} \xrightarrow{t^0} 2ZnO\\
{n_{Zn}} = \dfrac{m}{M} = \dfrac{{13}}{{65}} = 0,2\,mol\\
{A_{Zn}} = n \times N = 0,2 \times 6 \times {10^{23}} = 1,2 \times {10^{23}}\\
b)\\
{n_{{O_2}}} = \dfrac{{{n_{Zn}}}}{2} = \dfrac{{0,2}}{2} = 0,1\,mol\\
{A_{{O_2}}} = n \times N = 0,1 \times 6 \times {10^{23}} = 6 \times {10^{22}}\\
{V_{{O_2}}} = n \times 22,4 = 0,1 \times 22,4 = 2,24l\\
c)\\
{V_{kk}} = 2,24 \times \dfrac{{100}}{{20}} = 11,2l\\
d)\\
{n_{ZnO}} = {n_{ZnO}} = 0,2\,mol\\
{m_{ZnO}} = n \times M = 0,2 \times 81 = 16,2g
\end{array}\)