Ozone Free Radical Substitution

追加: 2026-05-22

[00:00:00]A problem in the world currently is ozone depletion by free radical substitution. This can happen by two main things. One are called CFCs, which are chlorofluorocarbons, and the other is nitrogen radicals.

[00:00:12]So, if we focus on the CFCs, these are in a lot of main or used to be in a lot of um refrigerators and stuff like that. So, they've been banned now because they used to go up into the air and react with UV light to form this radical and a chlorine radical. This was the major radical that caused issues.

[00:00:30]This chlorine radical reacted with ozone here to form ClO as a radical and O2.

[00:00:36]So, the ozone has been split into these two.

[00:00:39]And then this radical went on to react again with another molecule of ozone to produce the same Cl uh radical there and two molecules of uh that's meant to say O2, sorry.

[00:00:51]Not ozone, O2.

[00:00:53]But, if you if you um if you add these two together, that and that cancel cuz it's both used and made. That and that both cancel, so they're both used and made. And so, you get an overall equation of 2 O3, so ozone molecules, are being converted to oxygen. So, it's basically burning holes in the ozone layer.

[00:01:12]Ozone depletion via nitrogen radicals, however, a little bit different. These NO radicals are formed from like the fumes of cars, for example.

[00:01:21]And this reacts with ozone to form an NO2 radical and O2.

[00:01:26]And this NO2 radical reacts with just a single oxygen atom, not ozone, just the oxygen atom, uh to form an NO radical, so what we used up there, and O2.

[00:01:37]Overall, it's O3 plus O cuz that is used and made there and that is used and made there, so they cancel each other out to form two O2 molecules there.

[00:01:48]This O, if you're wondering where it's made from, is uh via basically the same process up here.

[00:01:54]O um And is converted to O2 plus O using UV light.

[00:02:00]Or oxygen is converted to two O atoms using UV light as well.

[00:02:06]The main pattern if they ever ask you to like write these equations out is just note that if it's made here it's going to be used here. If it's a radical, it's going to be used there.

[00:02:17]Uh if it gives the overall equation like this as well.

[00:02:20]And once again, if it starts off here it's going to be made here as well. And so same process here. Radical is formed, it's going to be used.

[00:02:30]And the radical is used, it's going to be formed cuz they cancel each other out. You can't really have a radical in an overall reaction because they're very reactive. So they're just not stable.