Question

In terms of hybridisation, bonding and stereochemistry, explain why alkenes are more chemically reactive than alkanes.

Answer 1

The high amount of P character in SP3 hybridized orbitals of the carbon in an alkane allows for more electron density to be aligned along the bond tragectory within the alkane

thus it forms strong and stable covalent bonds basically known as Sigma bonds ( single bonds).

Alkenes are SP2 hybridized and in SP2 hybridized orbitalsm more election density is situated around the core of the carbon nucleus and the pi orbitals in the pi bond are high in energy and therefore they are more available for bonding than electrons locked up in a sigma bond. There is also a steric factor as the SP2 system adopts an exposed planar structure.

So in conclusion energy required to break Sigma bond is more compared to pi bond. So double bond breaks easily in alkenes so they are less stable.