Empirical formula is a chemical formula that shows the simplest ratio of atoms of each element present in a compound.
Molecular formula is a chemical formula that shows the actual number of atoms of each element present in one molecule of a compound.
The empirical formula of an ionic compound is similar to its formula unit.
Example: the empirical formula of sodium chloride is NaCl; the formula unit of sodium chloride is NaCl.
The molecular formula of a molecular compound is a multiple of its empirical formula.
Example: The empirical formula of Glucose is CH2O; the molecular formula of Glucose is C6H12O6.
Molecular Formula = n(Empirical Formula)
n = integer (1, 2, 3…)