Em tham khảo nha:
\(\begin{array}{l}
2)\,C\\
3)\,B\\
4)\,A\\
3)\\
a)\\
4Al + 3{O_2} \xrightarrow{t^0} 2A{l_2}{O_3}\\
{n_{Al}} = \dfrac{{5,4}}{{27}} = 0,2\,mol\\
{n_{{O_2}}} = 0,2 \times \frac{3}{4} = 0,15\,mol\\
{V_{{O_2}}} = 0,15 \times 22,4 = 3,36l\\
b)\\
2KCl{O_3} \xrightarrow{t^0} 2KCl + 3{O_2}\\
{n_{KCl{O_3}}} = 0,15 \times \frac{2}{3} = 0,1\,mol\\
{m_{KCl{O_3}}} = 0,1 \times 122,5 = 12,25g
\end{array}\)
