Ozone in the upper atmoshphere can be destroyed by the following two step mechanism: Cl(g) + O3(g)

Question:

Ozone in the upper atmoshphere can be destroyed by the following two step mechanism:
Cl(g) + O3(g) → ClO(g) + O2(g)
Cl(g) + O(g) → ClO(g) + O2(g)
(a)What is the overall equation for this process?
(b) What is the catalyst in the reaction? How do you know?
(c) What is the intermediate in the reaction? How do you distinguish it from the catalyst?