Alkanes and alkenes

Alkanes and alkenes are two groups of hydrocarbon molecules.

Alkanes
Crude oil is made of a mixture of different alkane molecules. The three simplest alkanes are methane, ethane and propane. These compunds are found in natural gas.

Alkanes are saturated hydrocarbons. This means that all the bonds joining carbon atoms to each other are single bonds.

Alkenes
Alkenes are similar to alkanes, except that alkene molecules have at least one double bond between two of the carbon atoms. They are unsaturated molecules.

Names
The name sof all alkanes end in '-ane' and the names of all alkenes end '-ene'. The first part of the name tells you the number of cabron atoms in each molecule.
 * methane (CH4) has only one carbon atom
 * ethane (C2H6) AND ethene (C2H4) have two carbons atoms.
 * proane (C3H8) and proene (C3H6) have three carbon atoms.

The bromine test
The bromine test is used to find out if a liquid contains double bonds. Bromine water (bromine dissolved in water) is an orange liquid but becomes colourless when mixed with unsaturated molecules.