\(\begin{array}{l}
11)\\
Fe + 2HCl \to FeC{l_2} + {H_2}\\
2Na + 2{H_2}O \to 2NaOH + {H_2}\\
{P_2}{O_5} + 3{H_2}O \to 2{H_3}P{O_4}\\
12)\\
2{H_2} + {O_2} \to 2{H_2}O\\
Zn + 2HCl \to ZnC{l_2} + {H_2}\\
n{H_2} = n{H_2}O = \dfrac{m}{M} = \dfrac{{1,8}}{{18}} = 0,1\,mol\\
V{H_2} = n \times 22,4 = 0,1 \times 22,4 = 2,24l\\
nZn = n{H_2} = 0,1\,mol\\
mZn = n \times M = 0,1 \times 65 = 6,5g\\
13)\\
S + {O_2} \to S{O_2}\\
nS{O_2} = n{O_2} = \dfrac{V}{{22,4}} = \dfrac{{2,24}}{{22,4}} = 0,1\,mol\\
VS{O_2} = 0,1 \times 22,4 = 2,24l
\end{array}\)
