- interpret and use the general, structural, displayed and skeletal formulae of organic molecules
Different ways to represent an organic molecule

Molecular and empirical formulae
A molecular formula shows the number of each atom in a compound, while an empirical formula shows the simplest whole number ratio of the the combining atoms.
Compound | Molecular formula | Empirical formula |
---|---|---|
propane | C3H8 | C3H8 |
ethene | C2H4 | CH2 |
propene | C3H6 | CH2 |
ethanoic acid | C2H4O2 | CH2O |
Structural, displayed and skeletal formulae
While molecular formula only shows the number of each atom in a molecule, structural, displayed and skeletal formulae shows the arrangement of the atoms. A displayed formula shows both the relative position of atoms and the bonds between them. A structural formula shows the relative position of the atoms without showing the bonds. A skeletal formula, the simplest way of representing an organic compound, is similar to
Example 1: butane (C4H10)

Note that the displayed formula does not indicate the bond angles.
Example 2: 4-chloro-3-methylpentan-1-ol (C6H13ClO)

Example 3: ethyl propanoate (C5H10O2)
