\(a,n_{Fe_2O_3}=\dfrac{80}{160}=0,5\left(mol\right)\\ n_{H_2}=\dfrac{67,2}{22,4}=3\left(mol\right)\)
PTHH: \(Fe_2O_3+3H_2\rightarrow2Fe+3H_2O\)
Trước: 0,5 3
Trong; 0,5 1,5 1
Sau: 0 1,5 1
Vì \(\dfrac{0,5}{1}< \dfrac{3}{3}\) nên H2 dư
\(m_{H_2\left(dư\right)}=1,5.2=3\left(g\right)\)
b, \(m_{Fe}=56.1=56\left(g\right)\)
nFe2O3 = 80 : 160 = 0,5 (mol)
nH2 = 67,2 : 22,4 =3 (mol)
pthh : Fe2O3 + 3H2 -t--> 4Fe + 3H2O
LTL
0,5/1 < 3/3 => H2 du
theo pt , nFe = 4nFe2O3 = 2 (mol)
=> mFe = 2 .56 = 112 (g)