Write the molecular formulae for the following compounds and name the elements present.

(a) Baking soda

(b) Common salt

(c) Sulphuric acid

(d) Nitric acid

The valency of aluminium is 3. Write the valency of other radicals present in the following compounds.

(a) Aluminium chloride

(b) Aluminium oxide

(c) Aluminium nitride

(d) Aluminium sulphate

(a) What is a chemical equation?

(b) Why is it necessary to balance a chemical equation?

(c) What are the limitations of a chemical equation?

What are the ways by which a chemical equation can be made more informative?