Pb(NO₃)₂ + 2KI = 2KNO₃ + PbI₂↓
Pb²⁺+ 2NO₃⁻ + 2K⁺ + 2I⁻ = 2K⁺ + NO₃⁻ + PbI₂↓
Pb²⁺ + 2I⁻ = PbI₂↓
NiCl₂ + H₂S = 2HCl + NiS↓
Ni²⁺ + 2Cl + 2H⁺ + S²⁻ = 2H⁺ + 2Cl⁻ + NiS↓
Ni²⁺ + S²⁻ = NiS↓
K₂CO₃ + 2HCl = 2KCl + CO₂↑ + H₂O
2K⁺ + CO₃²⁻ + 2H⁺ + 2Cl⁻ = 2K⁺ + 2Cl⁻ + CO₂↑ + H₂O
CO₃²⁻ + 2H⁺ = CO₂↑ + H₂O
CuSO₄ +2NaOH = Na₂SO₄ +Cu(OH)₂↓
Cu²⁺ + SO₄²⁺ + 2Na⁺ + 2OH⁻ = 2Na⁺ + SO₄²⁻ +Cu(OH)₂↓
Cu²⁺ + 2OH⁻ = Cu(OH)₂↓