(a) When chlorine atoms react with atmospheric ozone, what are the products of the reaction? (b) Based on average bond enthalpies, would you expect a photon capable of dissociating a \(\mathrm{C}-\mathrm{Cl}\) bond to have sufficient energy to dissociate a \(\mathrm{C}-\mathrm{Br}\) bond? \((\mathbf{c})\) Would you expect the substance \(\mathrm{CFBr}_{3}\) to accelerate depletion of the ozone layer?

To find the reaction products when chlorine atoms react with atmospheric ozone, we need to start with the chemical reaction. The reaction of chlorine atoms with ozone can be represented as: Cl + O3 → ClO + O2 The reaction products are chlorine monoxide (ClO) and molecular oxygen (O2).

In this part of the exercise, we have to compare the energy required to dissociate a C-Cl bond with that of a C-Br bond. We will use the average bond enthalpies of C-Cl and C-Br bonds to make the comparison. The average bond enthalpy for C-Cl is approximately 339 kJ/mol, whereas the average bond enthalpy for C-Br is around 280 kJ/mol. If a photon has enough energy to dissociate a C-Cl bond, which has a higher bond enthalpy, then it should also have enough energy to dissociate a C-Br bond, which has a lower bond enthalpy.

Now we evaluate if the compound CFBr3 can accelerate the depletion of the ozone layer. To do that, we need to consider that ozone depletion occurs primarily by the release of radical halogen atoms, such as chlorine and bromine, into the atmosphere. The compound CFBr3 contains carbon, fluorine, and bromine atoms. Although fluorine is not known to participate in ozone depletion reactions, bromine is known to be a potent catalyst for ozone destruction. Bromine reacts with ozone (O3) to produce bromine monoxide (BrO) and molecular oxygen: Br + O3 → BrO + O2 And then, BrO can further react with a monatomic oxygen (O) to produce bromine (Br) and O2, allowing the cycle to repeat: BrO + O → Br + O2 Given that CFBr3 contains bromine, and considering the ozone depletion mechanism involving bromine species, it can be concluded that CFBr3 can potentially contribute to the acceleration of ozone layer depletion. In summary, the reaction between chlorine atoms and ozone produces chlorine monoxide (ClO) and molecular oxygen (O2). A photon capable of dissociating a C-Cl bond is likely to possess enough energy to dissociate a C-Br bond due to the lower bond enthalpy of the C-Br bond. Lastly, CFBr3 containing bromine may accelerate the depletion of the ozone layer by participating in ozone destruction reactions.