\(n_{FeO}=\dfrac{0,36}{72}=0,005\left(mol\right)\)
\(n_{H_2SO_4}=2n_{FeO}=0,01\left(mol\right)\\ \Rightarrow m_{ddH_2SO_4}=\dfrac{0,01.98}{98\%}=1\left(g\right)\\ n_{Fe_2\left(SO_4\right)_3}=\dfrac{1}{2}n_{FeO}=0,0025\left(mol\right)\\ \Rightarrow m_{Fe_2\left(SO_4\right)_3}=0,0025.400=1\left(g\right)\)
2FeO+4H2SO4->Fe2(SO4)3+SO2+4H2O
0,005---------------------0,0025-----0,0025
n FeO=0,005 mol
=>m Fe2(SO4)3=0,0025.400=1g