One of the Natural Processes That Destroys Ozone in the Atmosphere

Multiple Choice

One of the natural processes that destroys ozone in the atmosphere is postulated to consist of two steps:
O₃(g) + UV radiation → O₂(g) + O(g)
O₃(g) + O(g) → 2 O₂(g)
The standard enthalpies of formation for ozone and for atomic oxygen are +142.7 kJ/mol and +249.2 kJ/mol,respectively.What would be the standard energy change associated with the combination of ozone and atomic oxygen to form 50.0 L of molecular oxygen,measured at -75 °C and 0.12 atm?

A) -38 kJ
B) -72 kJ
C) -150 kJ
D) -196 kJ
E) -600 kJ