Em tham khảo nha :

\(\begin{array}{l}
2)\\
a)\\
\text{Chất tham gia : Magie , Axit Clohidric}\\
\text{Magie Clorua , khí Hidro}\\
b)\\
\text{Magie + Axit Clohidric} \to\text{Magie Clorua + khí Hidro} \\
3)\\
a)\\
4Na + {O_2} \to 2N{a_2}O\\
b)\\
2Al + F{e_2}{O_3} \to A{l_2}{O_3} + 2Fe\\
4)\\
{M_{C{O_2}}} = {M_C} + 2{M_O} = 44dvC\\
{d_{C{O_2}/kk}} = \dfrac{{44}}{{29}} = 1,517\\
5)\\
F{e_2}{O_3} + 3{H_2} \to 2Fe + 3{H_2}O\\
a)\\
{M_{F{e_2}{O_3}}} = \dfrac{m}{M} = \dfrac{{32}}{{160}} = 0,2mol\\
{n_{Fe}} = 2{n_{F{e_2}{O_3}}} = 0,2mol\\
{m_{Fe}} = n \times M = 0,2 \times 56 = 11,2g\\
c)\\
{n_{{H_2}O}} = \dfrac{m}{M} = \dfrac{{5,4}}{{18}} = 0,3mol\\
{n_{{H_2}}} = {n_{{H_2}O}} = 0,3mol\\
{V_{{H_2}}} = n \times 22,4 = 0,3 \times 22,4 = 6,72l
\end{array}\)