\(2Fe+6H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+SO_2+6H_2O\)
2x ___ 6x ______ x___________3x____________
\(Fe+Fe_2\left(SO_4\right)_3\rightarrow3FeSO_4\)
y ______ y ____________3y
\(\rightarrow n_{Fe}=2x+y=37,5\%.6x\)
\(m_{muoi}=400\left(x-y\right)+152.3y=8,28\)
\(\rightarrow\left\{{}\begin{matrix}x=0,02\\y=0,005\end{matrix}\right.\)
\(\rightarrow n_{Fe}=2x+y=0,045\)
\(\rightarrow m_{Fe}=2,52\left(g\right)\)