Properties of chlorofluorocarbons (CFCs)

Steps:

• Compare bond energies: C-Cl (~330 kJ/mol) breaks under stratospheric UV, but C-F (~485 kJ/mol) does not.
• Identify ozone depletion mechanism: UV breaks C-Cl, releasing Cl atoms that catalytically destroy O3 via Cl + O3 → ClO + O2 cycle.
• Define inertness: Strong bonds make CFCs unreactive in troposphere, allowing long atmospheric lifetime.
• Note D incompleteness prevents evaluation.

Why C is correct:

• CFCs are relatively chemically inert due to high C-F and C-Cl bond strengths, resisting reactions in lower atmosphere per basic organic chemistry stability principles.

Why the others are wrong:

• A: C-F bonds require higher energy than stratospheric UV provides, so only C-Cl dissociates readily.
• B: CFCs enable ozone depletion indirectly via Cl release, but do not cause it directly themselves.
• D: Not enough information.

Final answer: C