Final answer:
Chlorine atoms act as catalysts in the decomposition of ozone to oxygen by participating in a catalytic cycle that breaks down O3 molecules into O2. Similarly, nitric oxide aids in ozone depletion through its own catalytic cycle.
Step-by-step explanation:
Role of Chlorine in the Nitration Process
Chlorine atoms serve as effective catalysts in various chemical reactions, including the gas-phase transformation of ozone (O₃) to diatomic oxygen (O₂). The mechanism by which chlorine acts as a catalyst involves a series of steps in which chlorine atoms help to break the O₃ molecules into O₂:
- Chlorine atoms react with ozone (O₃) to form chlorine monoxide (ClO) and molecular oxygen (O₂).
- Chlorine monoxide (ClO) then reacts with another ozone molecule to release a chlorine atom and form two molecules of oxygen (O₂).
The released chlorine atom is then free to catalyze additional reactions of ozone decomposition. In this role, chlorine acts as a chain carrier, continually regenerating and perpetuating the reaction without being consumed.
Nitric Oxide and Ozone Decomposition
Nitric oxide (NO) also plays a substantial role in the atmospheric chemistry of ozone decomposition. The presence of NO can accelerate the breakdown of ozone by similar catalytic cycles:
- Nitric oxide reacts with ozone to produce nitrogen dioxide (NO₂) and oxygen (O₂).
- Nitrogen dioxide can then react with free oxygen atoms to regenerate nitric oxide and release additional O₂.
As a result, both chlorine and nitric oxide facilitate a catalytic cycle, contributing to the depletion of ozone in the atmosphere.