Ozone Chemistry
Heather Price
North Seattle College
If our earth were the size of an apple or orange, which
skin represents the thickness of our atmosphere?
Natural Ozone production (Chapman Cycle)
O2 + UV-C light  O + O
O2 + O O3
O3  O2+ O
CFCs deplete stratospheric ozone
(1995 Nobel Prize in Chemistry)
CF2Cl2 + UV-C light  CF2Cl + Cl
Cl + O3  ClO + O2
ClO + O  Cl + O2
O3 + O  2O2
Associated Press 1995. F. Sherwood Rowland,
left, accepting the Nobel Prize in 1995 from King
Carl XVI Gustaf of Sweden.
“Is it enough for a scientist simply to
publish a paper? Isn’t it a responsibility
of scientists, if you believe that you
have found something that can affect
the environment, isn’t it your
responsibility to actually do something
about it, enough so that action actually
takes place?… If not us, who? If not
now, when?”
-F. Sherwood Rowland, 1997
Ozone hole is repairing thanks the Montreal Protocol
which required the phase out of CFCs worldwide
• BBC 2014 News Report on Ozone hole recovery
• NASA Goddard Space Center News Report on 2014 Ozone hole recovery
• General Questions
• What are the causes of the depletion of our ozone layer?
• What is the chemical reaction that displays how ozone is created?
• Which reactions demonstrate the destruction of the ozone layer?
• How do CFC's destroy the ozone layer?
• Why should regulations be enforced now in regards to pollution and
harmful chemicals?
• What type of atom in the CFC molecule is most destructive to the
ozone?
• In which layer of the atmosphere does the ozone layer?
• What cycle is responsible for natural ozone in the stratosphere?
• What factor is responsible for breaking up stable molecules such as
ozone and CFCs in the stratosphere?
General Questions Answers
•What are the causes of the depletion of our ozone layer?
• the release of free radicals, the use of CFC's, the excessive burning of fossil fuels
•What is the chemical reaction that displays how ozone is created?
• UV + O2 -> 2O + heat, O2 + O -> O3, O3 + O -> 2O2
•Which reactions demonstrate the destruction of the ozone layer?
• Cl + O3 ------> ClO + O2 and ClO + O ------> Cl + O
•How do CFC's destroy the ozone layer?
• the atomic chlorine freed from CFC reacts in a catalytic manner with ozone and atomic oxygen to make more
oxygen molecules
•Why should regulations be enforced now in regards to pollution and harmful chemicals?
• without regulation, the production and use of chemicals will run out of hand and do irreversible damage to
the stratosphere
•What type of atom in the CFC molecule is most destructive to the ozone?
• chlorine
•In which layer of the atmosphere does the ozone layer?
• the stratosphere, the second closest to the Earth's surface
•What cycle is responsible for ozone in the stratosphere?
• the Chapman cycle
•What factor is responsible for breaking up stable molecules?
• ultraviolet rays from the sun