Write the reaction equations: a) Ca = CaO = Ca (OH) 2 = CaCl 2 = Ca b) Mg = MgO = MgSO4 = Mg (NO3) 2

A) 1) 2Ca + O2 → 2CaO (compound reaction; calcium, oxygen, calcium oxide);

2) CaO + H2O → Ca (OH) 2 ↓ (compound reaction; calcium oxide, water; calcium hydroxide);

3) Ca (OH) 2 ↓ + 2HCl → CaCl2 + 2H2O (exchange reaction; calcium hydroxide, hydrochloric acid, calcium chloride, water);

4) CaCl2 → Ca + Cl2 (decomposition reaction; calcium chloride, calcium, chlorine).

B) 1) 2Mg + O2 → 2MgO (compound reaction; magnesium, oxygen, magnesium oxide);

2) MgO + H2SO4 → MgSO4 + H2O (exchange reaction; magnesium oxide, sulfuric acid, magnesium sulfate, water);

3) MgSO4 + Ba (NO3) 2 → BaSO4 + Mg (NO3) 2 (exchange reaction; magnesium sulfate, barium nitrate, barium sulfate, magnesium nitrate).