Em tham khảo nha :
\(\begin{array}{l}
1)\\
2{H_2} + {O_2} \xrightarrow{t^0} 2{H_2}O\\
3Fe + 2{O_2} \xrightarrow{t^0} F{e_3}{O_4}\\
2Cu + {O_2} \xrightarrow{t^0} 2CuO\\
C + {O_2} \xrightarrow{t^0} C{O_2}\\
2)\\
4P + 5{O_2} \xrightarrow{t^0} 2{P_2}{O_5}\\
{n_{{P_2}{O_5}}} = \dfrac{m}{M} = \dfrac{{28,4}}{{142}} = 0,2mol\\
{n_P} = 2{n_{{P_2}{O_5}}} = 0,4mol\\
{m_P} = 0,4 \times 31 = 12,4g\\
{n_{{O_2}}} = \dfrac{5}{2}{n_{{P_2}{O_5}}} = 0,5mol\\
{V_{{O_2}}} = 0,5 \times 22,4 = 11,2l\\
b)\\
2KMn{O_4} \xrightarrow{t^0} {K_2}Mn{O_4} + Mn{O_2} + {O_2}\\
{n_{KMn{O_4}}} = 2{n_{{O_2}}} = 1mol\\
{m_{KMn{O_4}}} = 1 \times 158 = 158g
\end{array}\)
