Alkynes exhibit and chain isomerism and position isomerism
The arrangement of the chain is different in these isomers
Ex: Pent-1-yne Linear chain pentyne with triple bond at the terminal carbon.
3-Methylbut-1-yne - branched isomer having a methyl group at the 3rd carbon and triple at the terminal carbon.
Position isomerism - position of triple bond changes. Alkynes having more than four carbon atoms exhibit this isomerism.
1-Alkyne 2 Alkyne
Alkynes do not have geometrical isomerism as the bond angle is 180°