CFCs and Ozone (1 Viewer)

[beemz]

ummmm ok
so CFCs are manufactuered hydrocarbons with cholrine and fluroine replacing some hydrogens...
the whole big thing about them is that they go up into the stratosphere get broken down by energy from the uv radiation.

this is a problem becuase halogens react with the ozone????
to form an oxide. with ozone not being replaced.

fluroine and chlorine are both halognes? so why does every text book and site only focus on chlorine reacting with ozone???
(or in the case of halons- bromine)

so is it not halognes that react? is i just Cl? what happnes to the F???




and completely off topic. but methane and other greenhouse gases which trap radiation in the atmosphere, why also do they not prevent radiation coming in?

 

[Sparcod]

Here's what I know.
Ozone is an 'absorber' of UV light, because when they are hit by them, an oxyegen molecule and an oxygen radical form. Then they reform.

When a CFC is photodissociated, a chlorine radical forms and reacts with the 03 ozone. and ClO is formed.

Note, halons such as bromine are worse because BrO is very reactive...

 

[beemz]

ah so ah...
Fluorine deosnt react becuase there is no fluorine free radical formed?
what determines their reactivity? :$ the intermolecular forces? ie. BrO isnt held togehter very tightly... so its reactive coz it will break/ eact with other stuff?....
and Fluorine whatever its with is unreactive becuase the electronegativity it has is really big so it holds on..
ooo..
i have no idea what im talking about
but yes, thanks

 

[onebytwo]

i thought methane was capable of reacting with chlorine free radicals and remove them to prevent further damage to ozone layer.

 

[mitsui]

i thought methane was capable of reacting with chlorine free radicals and remove them to prevent further damage to ozone layer.

yes it does
it is one of the "steps to solve" they asked for in the syllabus

 

[tristambrown]

According to Roland smith (sonquering chemistry ed4) and wikipedia only Bromine (eg Halons and methyl bromide) and Chlorine (CFC's and HCFC's) screw O3.. apparently fluorine is fine :/ buggered if i know why

Re methane - yes it does have that capability. It however causes it's own problems in the atmosphere. Also most of it never reaches that point as it is destroyed long before it reaches that height ..

the only reason the CFC's make it there is because they are so bloody inert

 

[gem010]

http://www.bom.gov.au/lam/Students_Teachers/ozanim/ozoanim.shtml

it's solid gold =)

 

[BigBear_25]

fluroine and chlorine are both halognes? so why does every text book and site only focus on chlorine reacting with ozone???
(or in the case of halons- bromine)

so is it not halognes that react? is i just Cl? what happnes to the F???

From what I understand the reactiveness of halogens works up the period

that is flourine is more reactive than chlorine and bromine.

But in saying that I think that when a CFC is broken down the F radical forms a

diatomic molecule and so creates F2 rather than FO like chlorine makes ClO.

I think thats the correct explaination.

 

[beemz]

yeah nice link gem010
so F stays with the orignal molecule..
coool..
thanks all