Describe how the molecular structures of alkenes and alkynes differ from the structure of alkanes

Alkanes are saturated hydrocarbon that contains only single bonds, whereas Alkenes and Alkynes are unsaturated hydrocarbons which contain one or more double bond and triple bonds.

Explanation:

A saturated hydrocarbon with an only single bond is called alkanes. Ethane consisting of two carbon atoms that are bonded with a single bond and six hydrogen atoms sharing the other valence electron of carbon atoms. The molecular structure of alkane is CnH2n+2. An unsaturated hydrocarbon with a two bond is called alkenes. Ethene consisting of two carbon atoms double-bonded to each other. The molecular structure of alkene is CnH2n. An unsaturated hydrocarbon with a triple bond is called as alkynes. It involves sharing three pairs of electrons. The molecular structure of alkyne is CnH2n-2.