Em tham khảo nha:
\(\begin{array}{l}
1)\\
a)\\
Fe + B{r_2} \to FeB{r_2}\\
Fe:Br:FeB{r_2} = 1:1:1\\
b)\\
BaC{l_2} + 2AgN{O_3} \to Ba{(N{O_3})_2} + 2AgCl\\
BaC{l_2}:AgN{O_3}:Ba{(N{O_3})_2}:AgCl = 1:2:1:2\\
2)\\
{M_{{H_2}S}} = 1 \times 2 + 32 = 34\,g/mol\\
\% {m_H} = \dfrac{{1 \times 2}}{{34}} \times 100\% = 5,88\% \\
\% {m_S} = 100 - 5,88 = 94,12\% \\
3)\\
a)\\
{m_{{H_2}S{O_3}}} = n \times M = 0,5 \times 82 = 41g\\
{m_{NaOH}} = n \times M = 0,3 \times 40 = 12g\\
b)\\
{V_{{H_2}}} = n \times 22,4 = 0,5 \times 22,4 = 11,2l\\
{V_{{O_2}}} = n \times 22,4 = 0,1 \times 22,4 = 2,24l
\end{array}\)
