Answer:

Percentage composition of a compound is a ratio of an amount of each element to the total amount of individual elements in a compound, which is then multiplied with 100. Let us take an example of H2O i.e. Water. Water has 2 molecules of hydrogen, and one mole of water is of 18.0152 grams. And one mole of a hydrogen atom is of 1.008 grams. So, 2 hydrogen moles weighs 2.016 grams. Hence, one mole of water has 2.016 grams of hydrogen mole. Therefore, the percentage composition of hydrogen would be 2.016/18.0152 = 11.19%. Now let us study in detail about Percentage composition and its formula.