NaOH + HNO₃ = NaNO₃ + H₂O; Na⁺ + OH⁻ + H⁺ + NO₃⁻ = Na⁺ + NO₃⁻ + H₂O; OH⁻ + H⁺ = H₂O. K₂CO₃ + 2HCl = 2KCl + CO₂↑ + H₂O; 2K⁺ + CO₃²⁻ + 2H⁺ + 2Cl⁻ = 2K⁺ + 2Cl⁻ + CO₂↑ + H₂O; CO₃²⁻ + 2H⁺ = CO₂↑ + H₂O. CuSO₄ + 2KOH = K₂SO₄ + Cu(OH)₂↓; Cu²⁺ + SO₄²⁻ + 2K⁺ + 2OH⁻ = 2K⁺ + SO₄²⁻ + Cu(OH)₂↓; Cu²⁺ + 2OH⁻ = Cu(OH)₂↓.