MCQ
$\text{CFCs}$ deplete the ozone layer because:
- AThey release $\ce{Cl_2}$ gas.
- ✓They release chlorine free radical.
- CThey release $\ce{F_2}$ gas.
- DBoth $(a)$ and $(b).$
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Step $I\,\,:$ ${H_2}O(g)\, \to \,H(g)\, + \,OH(g)\,;$ $\Delta H = 498\,kJ\,mol^{-1}$
Step $II\,\,:$ $OH(g)\, \to \,H(g)\, + \,O(g)\,;$ $\Delta H = 428\,kJ\,mol^{-1}$
The bond enthalpy of the $O-H$ bond is....$kJ\,mol^{-1}$