NEET2002ChemistryChemical Bonding and Molecular StructureActual
Assertion : Sigma ( is a strong bond, while pi ( ) is a weak bond. Reason : Atoms rotate freely about pi ( ) bond.
Options
- AIf both the assertion and reason are true and reason is a correct explanation of the assertion.
- BIf both assertion and reason are true but assertion is not a correct explanation of the assertion.
- CIf the assertion is true but the reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If the assertion is true but the reason is false.
Step-by-step solution
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 orbitals. Pi bonding ( ) involves sidewise overlapping of the two atomic orbitals e.g. between p and p orbitals. Overlapping of orbitals is more effective in bonding than in -bonding. Due to the geometry of overlapping or orbitals, rotation of one atom is not possible around -bonds.