Em tham khảo nha :

\(\begin{array}{l}
3)\\
a)\\
BaC{l_2} + 2AgN{O_3} \to Ba{(N{O_3})_2} + 2AgCl\\
{n_{BaC{l_2}}} = \dfrac{m}{M} = \dfrac{{41,6}}{{208}} = 0,2mol\\
{n_{AgN{O_3}}} = 2{n_{BaC{l_2}}} = 0,4mol\\
{m_{AgN{O_3}}} = n \times M = 0,4 \times 170 = 68g\\
b)\\
{n_{AgCl}} = 2{n_{BaC{l_2}}} = 0,4mol\\
{m_{AgCl}} = n \times M = 0,4 \times 143,5 = 57,4g\\
4)\\
a)\\
2C + F{e_3}{O_4} \to 2C{O_2} + 3Fe\\
b)\\
{n_C} = \dfrac{m}{M} = \dfrac{{24}}{{12}} = 2mol\\
{n_{F{e_3}{O_4}}} = \dfrac{{{n_C}}}{2} = 1mol\\
{m_{F{e_3}{O_4}}} = n \times M = 1 \times 232 = 232g\\
c)\\
{n_{Fe}} = \dfrac{3}{2}{n_C} = 3mol\\
{m_{Fe}} = n \times M = 3 \times 56 = 168g\\
{n_{C{O_2}}} = {n_C} = 2mol\\
{V_{C{O_2}}} = n \times 22,4 = 2 \times 22,4 = 44,8l
\end{array}\)