а) H₂SO₄ + BaCI₂ = BaSO₄↓ + 2HCI
2H⁺ + SO₄²⁻ + Ba²⁺ + 2CI⁻ = BaSO₄↓ + 2H⁺ + 2CI⁻
SO₄²⁻ + Ba²⁺ = BaSO₄↓
б) 3NaOH + H₃PO₄ = Na₃PO₄ + 3H₂O
3Na⁺ + 3OH⁻ + 3H⁺ + PO₄³⁻ = 3Na⁺ + PO₄³⁻ + 3H₂O
3OH⁻ + 3H⁺ = 3H₂O
в) Ba(OH)₂ + Na₂CO₃ = BaCO₃↓ + 2NaOH
Ba²⁺ + 2OH⁻ + 2Na⁺ + CO₃²⁻ = BaCO₃↓ + 2Na⁺ + 2OH⁻
Ba²⁺ + CO₃²⁻ = BaCO₃↓
г) Na₂S + 2HCI = H₂S↑ + 2NaCI
2Na⁺ + S²⁻ + 2H⁺ + 2CI⁻ = H₂S↑ + 2Na⁺ + CI⁻
+ S²⁻ + 2H⁺ = H₂S↑