Differences between Empirical Formula and Molecular Formula - QS Study
QS Study

Differences between Empirical Formula and Molecular Formula:

Empirical Formula

1. The formula which gives the simple whole number ratio of the atom of various elements present in one molecule of the compound is called empirical formula.

2. The empirical formula expresses the elements by which it is formed.

3. It is determined by knowing the percentage of the elements of the compounds.

4. Sometimes the molecular formula and empirical formula of any compound become identical. E.g. HCI

5. Empirical formula of different compounds can be same.
e.g.: Empirical formula of Benzene and ethyne is CH.

6. Empirical formula is only for compound.

Molecular Formula

1. The formula which gives the actual number of atoms of various elements present in one molecule of the compound is called molecular formula.

2. This formula expresses the molecular structure of the compound or element.

3. It can be determined by knowing the percentage of elements and the molecular mass of the compounds.

4. Molecular formula of any compound sometimes becomes identical with empirical formula and sometimes it becomes multiple of the empirical formula.
e.g. H2O (empirical formula H20)
C6H6 (empirical formula CH)

5. Molecular formula of any compound is always fixed except isomerism.
e.g.: The molecular formula of Benzene and ethyne are respectively C6H6 and C2H2.

6. Molecular formula is for both compounds and elements.