Exemplar Problems

Problem 22 : Explain the concept of a sigma (σ) bond and a pi (π) bond in covalent bonds. Provide examples of molecules with sigma and pi bonds.

Solution :

Sigma (σ) bonds result from head-on overlap of atomic orbitals, allowing free rotation. Pi (π) bonds result from side-to-side overlap of p orbitals and restrict rotation. In molecules like ethene (C₂H₄), there’s one sigma (σ) and one pi (π) bond between carbon atoms.