The percentage of any element or constituent in a compound is the number of parts by mass of that element or constituent present in 100 parts by mass of the compound. It can be determined by the following two steps
1. Calculation of the molecular mass
Calculate the molecular weight of the compound from its formula by adding the atomic masses of the elements present.
2. Calculation of the percentage composition of the constituents
The percentage can be calculated by using the following relation:
