1) Fe2O3 + 3H2SO4 -> Fe2(SO4)3 + 3H2O
Fe2O3 + 6H[+] + 3SO4[2-] -> 2Fe[+3] + 3SO4[2-] + 3H2O
Fe2O3 + 6H[+] -> 2Fe[+3] + 3H2O
2) Fe2(SO4)3 + 6NaOH -> 3Na2SO4 + 2Fe(OH)3
2Fe[+3] + 3SO4[2-] + 6Na[+] + 6OH[-] -> 6Na[+] + 3SO4[2-] + 2Fe(OH)3
Fe[+3] + 3OH[-] -> Fe(OH)3
3) Fe(OH)3 + 3HCl -> FeCl3 + 3H2O
Fe(OH)3 + 3H[+] + 3Cl[-] -> Fe[+3] + 3Cl[-] + 3H2O
Fe(OH)3 + 3H[+] -> Fe[+3] + 3H2O
Прошу вас.