Organic formulae, naming and properties

A molecular formula counts atoms but does not show their connections. Condensed and skeletal formulae show connectivity more efficiently. In skeletal structures, each unlabelled line end or corner is a carbon, and enough carbon-bound hydrogens are implied to give carbon four bonds. Heteroatoms and their attached hydrogens are shown. Isomers have the same molecular formula but different structures.

Choose a parent chain containing the principal functional group, number it to locate that group and then name substituents. Compare properties using molecular size, polarity and hydrogen-bonding ability. Larger similar molecules generally have stronger dispersion forces. Hydrogen bonding often raises boiling point, while a long non-polar region can reduce water solubility. Condensation joins molecules while releasing a small molecule such as water.

Watch out: Isomers can have different atom connections and properties despite the same atom counts.