1) chemical formula (molecular formula) shows the total number and kinds of atoms in a molecule, but not their structural arrangement.
For example C₄H₂N₂O₄, molecular formula shows that compound has four carbon, two hydrogen, two nitrogen and four oxygen atoms.
2) The structural formula is a graphic representation of the molecular structure, it shows arrangement of the atoms and the covalent bonds between them.
For example, structural formula for hydrochloric acid is H-Cl.
