Đặt \(\left\{{}\begin{matrix}n_{Fe}=x\left(mol\right)\\n_{Na_2SO_3}=y\left(mol\right)\end{matrix}\right.\)
\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
x ---> x ----------> x -------> x
\(Na_2SO_3+H_2SO_4\rightarrow Na_2SO_4+H_2O+SO_2\)
y -----------> y -----------> y ------------------> y
Có: \(d_Y=13,4.2=26,8\left(\dfrac{g}{mol}\right)\)
\(\Rightarrow\dfrac{m_Y}{n_Y}=26,8\left(\dfrac{g}{mol}\right)\\ \Leftrightarrow\dfrac{2x+64y}{x+y}=26,8\)
\(\Rightarrow\dfrac{x}{y}=1,5\Leftrightarrow x-1,5y=0\left(1\right)\)
Mặt khác có: \(n_Y=x+y=0,02\left(2\right)\)
Từ (1), (2) giải được: \(\left\{{}\begin{matrix}x=0,012\\y=0,008\end{matrix}\right.\)
\(m=m_{Fe}+m_{Na_2SO_3}=56x+126y=56.0,012+126.0,008=1,68\left(g\right)\)
\(m_{dd.H_2SO_4}=\dfrac{\left(0,012+0,008\right).98.100\%}{20\%}=9,8\left(g\right)\)
\(m_{dd}=1,68+9,8-2.0,012-64.0,008=10,944\left(g\right)\)
\(C\%_{FeSO_4}=\dfrac{152.0,012.100\%}{10,944}=16,67\%\)
\(C\%_{Na_2SO_4}=\dfrac{142.0,008.100\%}{10,944}=10,38\%\)