Question

Why do alkynes not show geometrical isomerism?

Answer 1

Answer:

In alkynes the two sp hybridized carbon atoms and the groups attached to them lie in the same plane and thus only two spatial arrangement is possible for them. Alkynes are linear and thus do not show geometrical isomerism.

Answer 2

Answer:

There are no geometric isomers with alkynes because there is only one other group bonded to the carbon atoms that are involved in the triple bond.