9.1/9.2 Stratospheric Ozone Depletion

good ozone

the protective layer in the stratosphere

bad ozone

ground level; photochemical oxidant (sunlight reacts with SO2 and NOs)

ozone function

absorbs the suns UV rays, allowing just enough for life on earth

step 1

O2 + UV-C → O + O

step 2

O + O2 → O3

CFCs

* chlorofluurocarbons
* nontoxic, nonflammable, very stable
* contain C, CL, and F
* found in refrigerants, propellants (aerosols), foam and packing materials

1

UV causes a chlorine atom to break way from the CFC molecule

2

the free chlorine atom hits an ozone molecule

3

the chlorine atom pulls one oxygen atom away

4

5

the result is another free chlorine atom

6

free chlorine will continue to deplete ozone in the stratopshere

catalyst

Cl acts as a _____ - it aids another reaction, but is not getting used up itself

100,000

1 Cl atom can break down ____ ozone molecules before it bonds with another Cl atom, creating Cl2 and stopping reactions

antarctic ozone hole

in the mid-80s it was noticed that there was a serious thinning of the layer over Antarctica

montreal protocol

 a global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS).