3.1 explain the terms homologous series, hydrocarbon, saturated, unsaturated, general formula and isomerism.

Organic chemistry

·        Homologous series       a “family” of carbon compounds that have the same general formula, similar chemical properties and show a regular trend in physical properties, e.g., boiling points, density or viscosity.

·        Hydrocarbon                 a compound that contains hydrogen and carbon only.

·        Saturated                     a compound that contains only single bonds between carbon atoms.

·        Unsaturated                  a compound that contains at least one double bond between carbon atoms.

·        General formula           a formula that shows algebraically the ratio between atoms in the compounds of a homologous series.

·        Isomerism              this occurs where compounds which have the same molecular formula (same number of atoms of each element) can have two or more different structures.  These molecules are called structural isomers.