Question

Assertion : Sigma (σ) is a strong bond, while pi (π) is a weak bond.

Reason: Atoms rotate freely about pi (π) bond

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option  (c) A is true but R is false

Explanation:

Sigma bonding involves end to end overlapping of the two atomic orbitals e.g., between s and s, s and p and p and p orbitais. Pi bonding (π) involves sidewise overlapping of the two atomic orbitals e.g., between p and p orbitals. Overiapping of orbitals is more effective in σ-bonding than in π-bonding. Due to the geometry of the overlapping orbitals, rotation of an atom is not possible around π-bond.