Describe the difference between alkanes and alkenes.

Alkanes are saturated hydrocarbons, while alkenes are unsaturated hydrocarbons with at least one double bond.

Alkanes are hydrocarbons that only contain single covalent bonds between carbon atoms. They are also known as saturated hydrocarbons because they are fully saturated with hydrogen atoms. Alkanes have a general formula of CnH2n+2, where n is the number of carbon atoms in the molecule. They are relatively unreactive and are used as fuels and lubricants.

Alkenes, on the other hand, are hydrocarbons that contain at least one carbon-carbon double bond. They are also known as unsaturated hydrocarbons because they have fewer hydrogen atoms than alkanes. Alkenes have a general formula of CnH2n, where n is the number of carbon atoms in the molecule. The double bond makes them more reactive than alkanes and they can undergo addition reactions with other molecules.

The physical properties of alkanes and alkenes also differ. Alkanes are generally less dense than water and have lower boiling points than alkenes of similar molecular weight. Alkenes are more polar than alkanes due to the presence of the double bond, which can lead to stronger intermolecular forces and higher boiling points.

In summary, alkanes and alkenes are two types of hydrocarbons with different structures and properties. Alkanes are saturated and unreactive, while alkenes are unsaturated and more reactive due to the presence of a carbon-carbon double bond.