a)\(Fe2O3+3H2-->2Fe+3H2O\)
b)\(n_{H2}=\frac{6,72}{22,4}=0,3\left(mol\right)\)
\(n_{Fe2O3}=\frac{1}{3}n_{H2}=0,1\left(mol\right)\)
\(m_{Fe2O3}=0,1.260=16\left(g\right)\)
c)\(n_{Fe}=\frac{2}{3}nH2=0,2\left(mol\right)\)
\(m_{Fe}=0,2.56=11,2\left(g\right)\)