Explain the following reactions giving their balanced chemical equations :
Steam is passed over iron.

Explain the following reactions giving their balanced chemical equations : Lead is added to copper sulphate solution.

Steam is passed over aluminium.

Explain the following reactions giving their balanced chemical equations : Iron is treated with dil. Hydrochloric acid.

Explain the following reactions giving their balanced chemical equations : Calcium oxide is mixed with water. Give balanced reaction.

Explain the following chemical reactions and write the balanced chemical equations. Sugar is heated (charred.)

Explain the following chemical reactions and write the balanced chemical equations. Copper added to concentrated nitric acid.

Explain the following chemical reactions and write the balanced chemical equations. Copper to dilute nitric acid.