1. Write and balance the chemical equation when aluminum reactswith the oxygen in the air to generate alminum oxide.
2. Write and balance the chemical equation when hydrogenreacts with the oxygen in the air to fenerate water.
3. Write and balance the chemical equation when magnesiumreplaces the hydrogen in an aqueous solution of hydrogen chlorideto form magnesium chloride and hydrogen gas.
4. Write and balance the chemical equation when an aqueoussolution of barium chloride reacts with an aqueous soultion ofpotassium sulfate to produce barium sulfate, which does notdissolve in water, and potassium chloride, which remains insolution.