CHEMISTRY COMMUNITY

Do pi bonds only occur when there is a double or triple bond?
And if so, what is the reasoning for this? Like what makes this a pi bond and not a double sigma bond?

There can only be one sigma bond, because only one s orbital can be hybridized with multiple p orbitals, therefore, a double sigma bond cannot occur because two s orbitals are nowhere near each other and also cannot hybridize together.

Yes, pi bonds occur when there is a multiplicity of bonds. Hybridization is based on regions of electron density, not number of bonds, so the unhybridized orbitals form pi bonds.

A double bond needs both a pi bond and sigma bond. When two atoms are bound by more than one covalent bond, the additional orbitals overlap side by side to form pi bonds.