Turning oxygen into fluorine in our atmosphere

[Epsilon Eridani]

Summary:: Hypothetical discussion of a method to turn oxygen into fluorine through the use of another chemical and also discussing the biological effects of fluorine.

Hello,

I'd like to start this by saying my knowledge of chemistry is extremely basic. I barely graduated chemistry in high school, so please don't bash me too hard if what I'm about to write is silly. This discussion is entirely for artistic reasons and is not aimed at something in real life in any way, so I would understand if you don't find the time to discuss it.

I'm working on an art project and I'm looking into geoengineering (more specifically on Stratospheric Aerosol Injection) as a possible countermeasure to global warming.

So, imagine the planes go up and start saturating the stratosphere with something relatively harmless that can help with blocking out sunlight - sulfur, for example, which would form sulfur dioxide, and react with the water to create sulfuric acid (not sure if that is even possible, but let's imagine it is).

Now, suppose someone hijacked the project and replaced the sulfur in the plane tanks with gas that, when injected in the upper stratosphere, begins a violent reaction that turns oxygen molecules into fluorine ones. Are you still with me? Good. Now, if that were possible, and in a period of time the entire oxygen part of the atmosphere was replaced with fluorine, what would be a general outline of the events that would follow, simplified enough for a layman like me to understand?

It is my understanding that fluorine is a highly reactive gas that will react with pretty much anything it touches. What would happen to our atmosphere if all the oxygen was replaced with fluorine? What would the effect on biological lifeforms be? How would the oceans change?

I know this is a very vague and weird topic, but the nature of my project requires that it is at least somewhat scientifically accurate, so that's how I ended up here. A massive thank you to anyone who takes time out of their busy day to think about this and leave a reply here and educate my chemically-uneducated tuccus.

Take care, and stay safe!

 

[Borek]

the nature of my project requires that it is at least somewhat scientifically accurate

It is not, and it won't be. You can't covert one element into another using chemical methods. That calls for nuclear reactions.

I am afraid what you wrote is mostly a word salad randomly sprinkled with chemical terms. Plus, you have killed all life on Earth somewhere in the process.

 

[Epsilon Eridani]

Yes, I expected no less honest a reply. I know what I wrote sounds completely idiotic to someone that has at least basic chemistry knowledge. But is it really not possible to combine oxygen with something else that would lead to fluorine?

Plus, you have killed all life on Earth somewhere in the process.

That was the general idea of the whole thing.

 

[Drakkith]

But is it really not possible to combine oxygen with something else that would lead to fluorine?

It is not. Chemical reactions involve the exchange and/or sharing of electrons and changes molecules (groups of atoms) into different molecules, bonds atoms together to form molecules, or splits molecules apart into their constituent atoms. Changing one type of atom into another involves changing the number of protons in the nucleus, a process that requires some kind of nuclear reaction. This is both MUCH more difficult to do than chemical reactions and is FAR less controllable. It's the difference between requiring a few test tubes vs requiring a nuclear reactor or a particle accelerator.

 

[Epsilon Eridani]

Ok, so it is indeed much more complicated than I thought. Thanks for moving the thread btw, should've posted it there initially. Thanks for the reply.

One last question - which is the chlorofluorocarbon that breaks down ozone the quickest? It is my understanding that the Chlorine atoms are the real problem because they take one O atom from ozone, breaking it back down to O2. I read that 1 chlorine atom can break down 100,000 ozone atoms, but how much time does that process take approximately?

Also, it seems like after the chlorine atom bonds with an oxygen one, resulting in chlorine monoxide, it is possible that one more oxygen atom joins the fun, and the chlorine one can split off, leaving the O2 on its own, and resuming the ozone breakdown process again. Is that true, and if so - how long can this process go on for?

 

[TeethWhitener]

which is the chlorofluorocarbon that breaks down ozone the quickest?

https://en.wikipedia.org/wiki/Ozone_depletion_potential

I read that 1 chlorine atom can break down 100,000 ozone atoms, but how much time does that process take approximately?

Also, it seems like after the chlorine atom bonds with an oxygen one, resulting in chlorine monoxide, it is possible that one more oxygen atom joins the fun, and the chlorine one can split off, leaving the O2 on its own, and resuming the ozone breakdown process again. Is that true, and if so - how long can this process go on for?

This is how catalysis works: a very small amount of something (in this case, a Cl atom) is able to participate in a reaction and come out the other side in the same form it went in. In this case, the reaction is
$$2O_3 \rightarrow 3O_2$$
So the catalyzed reaction is
$$Cl\cdot + 2O_3 \rightarrow Cl\cdot + 3O_2$$
The chlorine atom facilitates the reaction without being consumed; therefore, it can go on to facilitate another reaction, and another and another etc. This keeps taking place until the Cl atom by happenstance reacts with something else (not ozone) and the product ceases to regenerate the Cl atom.

Sometimes you'll see this referred to as a chain reaction (or a radical chain reaction, most commonly seen with respect to the synthesis of polymers). The reaction has three steps: initiation (in this case, CFCs react with light to generate Cl atoms), propagation (Cl atoms react with ozone and are regenerated), and termination (Cl atoms react with something else that eliminates them from the mix). The amount of time this takes is governed by the kinetics; i.e., the detailed physics of the reaction and the concentrations of the different reagents in the atmosphere (since the initiation step is photoinduced, it will also depend on the time of day and how high in the sky the sun is). However, a good benchmark to get a feel for how fast the reactions involved are relative to each other is given by a rate constant.

I found this document:
http://www.columbia.edu/itc/chemistry/chem-c2407/hw/ozone_kinetics.pdf
the most important part of which is the comparison of ##k_4 \approx 10^{-15}cm^3molecule^{-1}sec^{-1}##, which is the rate constant for ozone degradation without chlorine participation, and ##k_6## or ##k_7##, the rate constants for ozone degradation with chlorine participation, both of which are on the order of ##10^{-11}cm^3molecule^{-1}sec^{-1}##.

Basically what this says is that the presence of chlorine in the reaction step:
$$O+O_3\rightarrow 2O_2$$
speeds up the reaction roughly 10,000 times. So where once you had an equilibrium between photoinduced ozone degradation and ozone regeneration, when you introduce chlorine atoms, the degradation suddenly goes 10,000 times faster, which is what leads to depletion of the ozone layer.