Introduction to Organic Chemistry

Organic chemistry is the study of carbon compounds. These molecules mainly contain carbon and hydrogen, but often include oxygen, nitrogen, and halogens. Carbon is unique because it has 4 valence electrons, allowing it to form 4 covalent bonds with other atoms. This creates an enormous variety of molecular structures.

Hydrocarbons are the simplest organic compounds, containing only carbon and hydrogen. They form the basis of fuels like petrol and natural gas. Within hydrocarbons, we distinguish between saturated compounds (containing only single C-C bonds, like alkanes) and unsaturated compounds (containing C=C double bonds, like alkenes).

Functional groups are specific atoms or groups within molecules that determine their chemical behaviour. The main functional groups include: alkanes (C-C single bonds), alkenes (C=C double bonds), alcohols (-OH group), and carboxylic acids (-COOH group). Each functional group gives compounds characteristic properties and reactions.

Organic compounds are named systematically based on the number of carbon atoms in the main chain and the functional group present. The prefix indicates chain length: meth- (1C), eth- (2C), prop- (3C), but- (4C), pent- (5C).

The suffix indicates the functional group: -ane for alkanes, -ene for alkenes, -ol for alcohols, and -oic acid for carboxylic acids. So ethanol is a 2-carbon alcohol, and propene is a 3-carbon alkene with a double bond.

Structural formulae show how atoms are arranged in a molecule. A displayed formula shows all bonds, while a skeletal formula shows the carbon backbone with bonds at angles. Understanding these representations is crucial for identifying isomers and predicting reactions.