Verified answer

1) SO3 + H2O = H2SO4

2) 3 SO3 + 2 Fe(OH)3 = Fe2(SO4)3 + 3 H2O

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

4) 3 H2SO4 + Fe2O3 = Fe2(SO4)3 + 3 H2O

5) Fe2O3 + 3 SO3 = Fe2(SO4)3

6) 2 Fe(OH)3 → 3 H2O + Fe2O3