a,
nFe2O3=\(\dfrac{21}{160}\)=0,13125(mol)
nH2=\(\dfrac{4,48}{22,4}\)=0,2(mol)
PTHH:
Fe2O3+3H2 (to)→2Fe+3H2O
Lập tỉ lệ :
\(\dfrac{0,131215}{1}\)>\(\dfrac{0,2}{3}\)
→ Sau phản ứng Fe2O3Fe2O3 dư,H2 hết
→nFe2O3 dư=0,13125−0,\(\dfrac{2.1}{3}\)=\(\dfrac{31}{480}\)(mol)
→mFe2O3 dư=\(\dfrac{31}{480}\).160≈10,3(g)
b,
nFe=\(\dfrac{2}{3}\)nH2=\(\dfrac{2}{3}\).0,2=\(\dfrac{2}{15}\)(mol)
→mFe=\(\dfrac{2}{15}\).56≈7,47(g)