A concern for the ozone layer was introduced in the 1970s when it was discovered

Question

A concern for the ozone layer was introduced in the 1970s when it was discovered that the presence of chlorine in the atmosphere could cause the second reaction to occur without the presence of UV light: This chlorine is believed to come from CFCs, chloroflurocarbons, hydrocarbons in which the hydrogens have been replaced by the halogens CI & F, CFCs are inert gases previously use in air conditioning and aerosol cans. One chlorine atom has the capability of converting 100,000 ozone molecules into oxygen over a period of a year or 2 before the chlorine is removed from the atmosphere, creating a major concern for humans, who need the ozone to protect them from the ultraviolet radiation. What role does chlorine play in this reaction? How can you tell?

Explanation / Answer

Cl acts as an intermediate to bring about the conversion of O3 to O2. To understand this we must first understand how it really works.

1. UV radiation strikes the CFC molecule to release a Cl radical. Now this free radical is very reactive.

2. This chlorine free radical strikes the O3 molecule and breaks away 1 Oxygen atom from O3 to form O2 and ClO.

3. Now another similar oxygen atom released from some other O3 molecule strikes the ClO to form O2 and release again Cl free radical and this Cl again follows above steps to break even more O3.

So we can say Chlorine acts as an Catalyst for the reaction of conversion of O3 to O2. We can safely say this because in the whole process Cl is not consumed.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.