Viết PTHH thực hiện những biến hoá sau: a) NaCl->Cl2->FeCl3->Fe(OH)3->Fe2(SO4)3 b) Al2O3-> Al->AlCl3->Al(OH)3->Al2O3 c) Fe(NO3)3->Fe(OH)3->Fe2O3->Fe->FeCl2->Fe(OH)2

Đáp án:a, 2H₂O+2NaCl⟶Cl₂+H₂+2NaOH

Cl₂+2FeCl₂→2FeCl₃

KOH+FeCl₃→KCl+Fe(OH)↓

3H₂SO₄+2Fe(OH)₃→Fe₂(SO₄)₃+6H₂O

b, 4Al+3O₂→2Al₂O₃

2Al+3Cl₂→2AlCl₃

2AlCl₃+3H₂O+3Na₂CO₃→2Al(OH)₃+6NaCl↓+3CO_2↑

2Al(OH)₃→Al₂O₃+3H₂O

c,3Ba(OH)₂+2Fe(NO₃)₃→3Ba(NO₃)₂+2Fe(OH)₃↓

2Fe(OH)₃→Fe₂O₃+3H₂O↑

Fe₂O₃+3H₂→2Fe+3H₂O

Fe+2FeCl₃→3FeCl₂

FeCl₂+2NaOH→NaCl+Fe(OH)₂

a)

2NaCl+2H2O->2NaOH+Cl2+2H2

2Fe+3Cl2->2FeCl3

FeCl3+3NaOH->Fe(OH)3+3NaCl

2Fe(OH)3+3H2SO4->Fe2(SO4)3+6H2O

b)

2Al2O3->4Al+3O2

2Al+6HCl->2AlCl3+3H2

AlCl3+3NaOH->Al(OH)3+3NaCl

2Al(OH)3->Al2O3+3H2O

c)

Fe(NO3)3+3NaOH->Fe(OH)3+3NaNO3

2Fe(OH)3->Fe2O3+3H2O

Fe2O3+3CO->2Fe+3CO2

Fe+2HCl->FeCl2+H2

FeCl2+2NaOH->Fe(OH)3+2NaCl