Mg → MgO → MgCl₂ → Mg(OH)₂ → MgO.
2Mg + O₂ = 2MgO
2Mg⁰ + O₂ = 2MgO
MgO + 2HCl = MgCl₂ + H₂O;
MgO + 2H⁺ + 2Cl⁻ = Mg²⁺ + 2Cl⁻ + H₂O;
MgO + 2H⁺ = Mg²⁺ + H₂O.
MgCl₂ + 2NaOH = Mg(OH)₂↓ + 2NaCl;
Mg²⁺ + 2Cl⁻ + 2Na⁺ + 2OH⁻ = Mg(OH)₂↓ + 2Na⁺ + 2Cl⁻;
Mg²⁺ + 2OH⁻ = Mg(OH)₂↓.
Mg(OH)₂ → (t°) MgO + H₂O.