a)\(Fe2O3+3H2-->2Fe+3H2O\)
b)\(n_{H2}=\frac{6,72}{22,4}=0,3\left(mol\right)\)
\(n_{Fe}=\frac{2}{3}n_{H2}=0,2\left(mol\right)\)
\(m_{Fe}=0,2.56=11,2\left(g\right)\)
c)\(Fe+H2SO4-->FeSO4+H2\)
\(n_{H2SO4}=n_{Fe}=0,2\left(mol\right)\)
\(m_{H2SO4}=0,2.98=19,6\left(g\right)\)