Addition Reactions

Unsaturated hydrocarbons such as alkenes and alkynes are extremely reactive towards a wide variety of reagents. The carbon-carbon double bond (–C=C–) of an alkene contains two types of bonds - one σ (sigma) bond and another π (pi) bond. In alkynes, out of the three carbon-carbon bonds, one is σ (sigma) bond and the other two are π (pi) bonds.

The π (pi) bond is weaker than the σ (sigma) bond and breaks easily.