Си степенями окисления 4al + 3o2 = 2al2o3 al2o3 + 3h2 = 2al + 3h2o 2al+3cl2 = 2alcl3 alcl3 + 3naoh = al(oh)3 + 3nacl 2al(oh)3 =t=> al2o3 + 3h2o 2al(oh)3 + 3h2so4 = al2(so4)3 + 6h2o al2(so4)3 + 3ba(no3)2 = 2al(no3)3 + 3baso4↓ s + o2 = so2 2al+3s = al2s3 2al2s3 + 9o2 = 2al2o3 + 6so2 so2 + 2koh = k2so3 + h2o k2so3 + 2hcl = 2kcl + h2o + so2↑ 2so2+o2 = 2so3 so3 + 2naoh = na2so4 + h2o so3 + h2o=h2so4 3h2so4 + 2fe(oh)3 = fe2(so4)3 + 6h2o fe2(so4)3 + 6naoh = 2fe(oh)3 + 3na2so4 2fe(oh)3 =t=> fe2o3+3h2o fe2o3 + 3c = 2fe + 3co

4Al + 3O2 = 2Al2O3
Al⁰ - 3e = Al³⁺ x4
O2 - 4e = 2O²⁻ x3

Al2O3 + 3H2 = 2Al + 3H2O
Al³⁺ + 3e = Al⁰ x2
H2 - 2e = 2H⁺ x3

2Al+3Cl2 = 2AlCl3
Al⁰ - 3e = Al³⁺ x2
Cl2⁰ + 2e = 2Cl⁻ x3

AlCl3 + 3NaOH = Al(OH)3 + 3Na⁺Cl⁻
Al³⁺ + 3OH⁻ = Al(OH)3

2Al⁺³(OH)3 =t=> Al2⁺³O3 + 3H2⁺O⁻²
2Fe(OH)3 =t=> Fe2⁺³O3⁻²+3H2O (всё так и остаётся)

2Al(OH)3 + 3H2SO4 = Al2⁺³(S⁺⁶O4)3 + 6H2⁺O⁻²
Al(OH)3 + 3H⁺ = Al³⁺ + 3H2O

Al2(SO4)3 + 3Ba(NO3)2 = 2Al(N⁺⁵O3)3 + 3Ba⁺²S⁺⁶O4↓
Ba²⁺ + SO4²⁻ = BaSO4↓

S + O2 = SO2
S⁰ - 4e = S⁺⁴
O2 + 4e = 2O²⁻

2Al+3S = Al2S3
Al⁰ - 3e = Al³⁺ x2
S⁰ + 2e = S²⁻ x3

2Al2S3 + 9O2 = 2Al2O3 + 6SO2
S⁻² - 6e = S⁺⁴ x2
O2 + 4e = 2O²⁻ x3

SO2 + 2KOH = K2⁺S⁺⁴O3⁻² + H2O
SO2 + 2OH⁻ = SO3²⁻ + H2O

K2SO3 + 2HCl = 2K⁺Cl⁻ + H2O + S⁺⁴O2↑
SO3²⁻ + 2H⁺ = H2O + SO2

SO3 + 2NaOH = Na2⁺S⁺⁶O4⁻² + H2O
SO3 + 2OH⁻ = SO4²⁻ + H2O

SO3 + H2O = H2⁺S⁺⁶O4⁻²
SO3 + H2O = 2H⁺ + SO4²⁻

3H2SO4 + 2Fe(OH)3 = Fe2⁺³(S⁺⁶O4⁻²)3 + 6H2O
3H⁺ + Fe(OH)3 = Fe³⁺ + 3H2O

Fe2(SO4)3 + 6NaOH = 2Fe⁺³(OH)3 + 3Na2S⁺⁶O4
Fe³⁺ + 3OH⁻ = Fe(OH)3

2SO2+O2 = 2SO3
S⁺⁴ - 2e = S⁺⁶ x2
O2 + 4e = 2O⁻²

Fe2O3 + 3C = 2Fe + 3CO
Fe³⁺ + 3e = Fe⁰ x2
C⁰ - 2e = C²⁺ x3