- A10 molecules
- B100 molecules
- C1,000 molecules
- 100,000 molecules
Correct answer
100,000 molecules
Why
A single chlorine atom can destroy up to 100,000 ozone molecules through a catalytic chain reaction before being deactivated.
The concept behind this question
Ozone depletion potential (ODP) measures how much damage a compound does to stratospheric ozone, and chlorine is the culprit. CFCs carry the most chlorine and the highest ODP, HCFCs carry less and are transitional, and HFCs contain no chlorine and have an ODP of zero. Zero ODP is not the same as harmless — many HFCs have high global warming potential (GWP), which is what the more recent phase-down addresses.
More questions on this topic
- Which of the following refrigerants has the highest Ozone Depleting Potential (ODP)?
- Where is the ozone layer located?
- What does the ozone layer protect us from?
- Which element in refrigerants is primarily responsible for ozone depletion?
- What type of refrigerant is R-22?
- What happens to CFCs and HCFCs when they reach the stratosphere?
Exam-style practice question. Not an official EPA exam question.