\(PTHH:2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)
\(n_{NaOH}=\frac{50.24}{100.40}=0,3\left(mol\right)\)
\(PTHH:MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)
\(PTHH:Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)
\(n_{MgO}=x;n_{Fe_2O_3}=y\\ hpt:\left\{{}\begin{matrix}40x+160y=16\\x+3y=0,5.1-\frac{0,3}{2}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,05\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{MgO}=\frac{0,2.40}{16}.100\%=50\%\\\%m_{Fe_2O_3}=100-50=50\%\end{matrix}\right.\)