1.Ca + 2HCl = CaCl2 + H2↑
Ca⁰ + 2H⁺ + 2Cl⁻ = Ca²⁺ + 2Cl⁻+ H2↑
Ca⁰ + 2H⁺ = Ca²⁺ + H2↑
2. Ca(OH)2 + 2HCl = CaCl2 + 2H2O
Ca²⁺ + 2OH⁻ +2H⁺ +2Cl⁻ = Ca²⁺ +2Cl⁻ + 2H2O
2OH⁻ + 2H⁺ = 2H2O
3. CaSO4 + BaCl2 = CaCl2 + BaSO4 ↓
Сa²⁺ +SO4²⁻ + Ba²⁺ +2Cl⁻ = Ca²⁺ +2Cl⁻ +BaSO4 ↓
SO4²⁻ + Ba²⁺ = BaSO4 ↓