а). Na₂CO₃ + H₂SO₄ = Na₂SO₄ + CO₂↑ + H₂O;
2Na⁺ + CO₃²⁻ + 2H⁺ + SO₄²⁻ = 2Na⁺ + SO₄²⁻ + CO₂↑ + H₂O;
CO₃²⁻ + 2H⁺ = CO₂↑ + H₂O.
б). ZnSO₄ + 2KOH = Zn(OH)₂↓ + K₂SO₄;
Zn²⁺ + SO₄²⁻ + 2K⁺ + 2OH⁻ = Zn(OH)₂↓ + 2K⁺ + SO₄²⁻;
Zn²⁺ + 2OH⁻ = Zn(OH)₂↓.
в). Na₂SO₄ + Ba(NO₃)₂ = 2NaNO₃ + BaSO₄↓;
2Na⁺ + SO₄²⁻ + Ba²⁺ + 2NO₃⁻ = 2Na⁺ + 2NO₃⁻ + BaSO₄↓;
SO₄²⁻ + Ba²⁺ = BaSO₄↓.
г). AlCl₃ + 3NaOH = Al(OH)₃↓ + 3NaCl;
Al³⁺ + 3Cl⁻ + 3Na⁺ + 3OH⁻ = Al(OH)₃↓ + 3Na⁺ + 3Cl⁻;
Al³⁺ + 3OH⁻ = Al(OH)₃↓.
д). FeSO₄ + Na₂CO₃ = FeCO₃↓ + Na₂SO₄;
Fe²⁺ + SO₄²⁻ + 2Na⁺ + CO₃²⁻ = FeCO₃↓ + 2Na⁺ + SO₄²⁻;
Fe²⁺ + CO₃²⁻ = FeCO₃↓.