What is the difference between empirical, molecular, and structural formulas?
The empirical formula is the simplest whole number ratio that defines constituent atoms in a species.
The molecular formula indicates the actual numbers of atoms in a given molecule. It is always a mulitple of the empirical formula (and of course the multiple may be
The structural formula is a graphic representation of the molecular formula, and attempts show how the molecule is arranged in three dimensions.
See here for some further discussion.