Molecular Formula

Topic Content:

The molecular formula of a substance shows the actual number of atoms of each element present in one molecule of the substance.

For example, the molecular formula of hydrogen peroxide is H₂ O₂ . This shows that one molecule contains two hydrogen atoms and two oxygen atoms.

The molecular formula may be the same as the empirical formula, or it may be a whole-number multiple of it.

Relationship between Empirical and Molecular Formula:

To determine the molecular formula, first calculate the mass represented by the empirical formula. This is called the empirical formula mass .

\(\scriptsize n = \normalsize \frac{\text{Relative molecular mass}}{\text{Empirical formula mass}}\)

Here, n is a whole number showing how many times the empirical formula must be