Write the reaction equation: Mg → MgO → Mg (OH) 2 → MgCl2 → Mg (OH) 2

1) 2Mg + O2 = 2MgO (when magnesium interacts with oxygen, magnesium oxide (II) is formed, since magnesium is easily oxidized);

2) MgO + H2O = Mg (OH) 2 (when magnesium (II) oxide interacts with water, magnesium (II) hydroxide is formed, the reaction occurs when heated);

3) Mg (OH) 2 + 2HCl = MgCl2 + 2H2O (when magnesium (II) hydroxide interacts with hydrochloric acid, magnesium chloride and water are formed);

4) MgCl2 + Ca (OH) 2 = Mg (OH) 2 + CaCl2 (when magnesium chloride interacts with calcium hydroxide, magnesium hydroxide and calcium chloride are formed).