AS-Level Organic Chemistry (Introduction)

Functional Groups


Alkanes are, generally speaking, not very reactive. Reactions that arise in organic chemistry almost always occur because of chemical ‘groups’ that are bonded onto an alkane chains. These ‘groups’ are called functional groups; they can react with other organic molecules and reagents to produce new products.  It is the functional group of a molecule that dictates its chemistry, and its presence can enable us to predict how the molecule is likely to react.


When molecules have the same functional group, but differ only by the length of the carbon chains they have, we say they belong to the same homologous series. Molecules within the same homologous series will react in a similar (but not always the same) way as each other, because they share the same functional group. 


There are many different types of functional groups within organic chemistry. For AS level, you must be familiar with and recognise the following:





















Carboxylic Acid