State the important information obtained from the following in four points:

(a) A molecular formula of a compound.

(b) A balanced chemical equation for a reaction.

(a) The molecular formula of a compound gives the following information:

1. It represents one molecule of a compound.
2. The elements or ions present in the compound.
3. The number of each kind of atoms and ions present in one molecule of a compound and their ratio.
4. The molecular formula enables us to calculate the mass of one molecule of the compound if the atomic mass of each atom present in the molecule is known. Molecular mass is the algebraic sum of the masses of all the atoms present in a given molecule.

(b) A balanced chemical equation gives the following information:

1. It shows which substances are taking part in a chemical reaction and what products are obtained as a result of it (Qualitative).
2. It shows both the number of molecules and the number of atoms of each type involved in the reaction.
3. It enables us to calculate the actual amount (mass) of reactants and products involved and formed in the reaction if atomic mass of each of the elements involved in the reaction is known (Quantitative).
4. It makes the study of chemistry universally standardized.