Question

Alkynes are less reactive than alkenes towards electrophilic reagents. Explain.

Answer 1

In case of alkynes pi electrons are less available for the electrophilic attack due to the sp hybridisation, because they are tightly bonded by the carbon atoms.

Another reason is that alkynes would form vinyl carbocation during electrophilic addition, which is less stable than alkyl carbocation formed from the alkene.