June 20, 2021, 08:29:14 AM
Forum Rules: Read This Before Posting


Topic: Free Radical REaction  (Read 5534 times)

0 Members and 1 Guest are viewing this topic.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Free Radical REaction
« on: April 13, 2014, 03:31:43 PM »
1. The problem statement, all variables and given/known data
Lets say you have 1 liter of 2 mol/L methane and the same amount of chlorine. Lets also say that both are liquids since those are most likely to react. Now the only way they can both be liquids is if the temperature is as cold as an antarctic winter so this is not aqueous. Gases more often *Ignore me, I am impatient* the wrong way and solids don't react unless it is oxidization or dissolving.

Now the initiation step is forming the first molecule of HCl and Methyl.

Now the methyl and chlorine atom really want to react and for chloromethane

Now here are the questions.

How much chloromethane, dichloromethane, trichloromethane, and tetrachloromethane will there be?

How much of the more complicated alkanes like ethane and propane will there be?

How many molecules made up of more complicated alkanes and chlorine will there be?

Will at some point the chlorine go back to its normal state and the hydrogen go back to the carbon so that you have just methane, ethane, propane etc?



2. Relevant equations

CH4 + Cl2 = HCl + CH3Cl(this continues up to tetrachloromethane)
2 CH3Cl = Cl2 + C2H6(this can continue for much longer than the previous one can)

3. The attempt at a solution

2 M CH4 + 2 M Cl2 = 2 M HCL + 2 M CH3 + 2 M Cl
2 M Cl + 2 M CH3 = 2 M CH3Cl
2 M CH3Cl * 2 CH3Cl = 1 M C2H6 + 1 M Cl2

2 M HCl = 2 M H2 + 2 M Cl2

This obviously can't happen because than we have more chlorine than we started out with. Why? well that 1 M Cl2 from ethane + 2 M Cl2 from HCl is = 3 M Cl2 and we started with 2 M Cl2. Just like the number of each element the molarity has to be balanced. This is where I am stuck is figuring out the molarity of each compound at each step of the process not the compounds themselves.

If I were actually doing this I would need layers and layers of protection from the cold and poisinous chlorine(which will likely boil as I put it in but not so much that the molarity significantly decreases)


If this were aqueous would there be some likelihood(even if it is low) of Chlorine snatching a hydrogen from the water instead of from the methane and carboxylic acids, ethers, and alcohols starting to form as well as ethane, isopropyl groups, propane, butane etc?

Now the polymerization process is likely to continue to icosane but might reach icosahectane which is a 120 carbon straight chain alkane. Than of course you have all these branched chain alkanes.

Would any alkenes, alkynes, benzene derivatives, and toluene derivatives form?

I would need to add liquid oxygen, liquid nitrogen, liquid sulphur, liquid phosphorus, and liquid boron to get the rest of the carbon compounds if I was interested in those but would the phosphorus I put in be in the form of phosphate which is PO4? If so do I really need to add liquid oxygen to form
Alcohols
Ketones
(Methyl ethyl ketone)
Aldehydes
Acyl halides
Carbonates
Carboxylic acids
Esters
Methoxys
Peroxides
Ethers
Hemiacetals
Hemiketals
Acetals
Orthoesters
Heterocycles
Orthocarbonate esters
if I have liquid phosphate?

As for nitrogen here is the list:
Amides
Acetamides
Aminess
Imines
Imides
Azides
Azo compounds
Cyanates
Nitrates
Nitriles
Nitrites
Nitro compounds
Nitroso compounds
Pyridine derivatives

Here is the list for sulphur:
Thiols
Sulfides
Disulfides
Sulfoxides
Sulfones
Sulfinic acids
Sulfonic acids
Thiocyanates
Thiones
Thials

Here is the list for phosphorus:
Phosphines
Phosphonic acids
Phosphates
Phosphodiesters

Here is the list for boron:
Boronic acids
Boronic esters
Borinic acids
Borinic esters

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #1 on: April 13, 2014, 04:47:47 PM »
Now the only way they can both be liquids is if the temperature is as cold as an antarctic winter so this is not aqueous. Gases more often *Ignore me, I am impatient* the wrong way and solids don't react unless it is oxidization or dissolving.

I am struggling to follow this thread but the first paragraph contains an incorrect statement so might as well start there.

Both methane and chlorine will be liquids at temperatures well above their "antarctic winter" boiling point if the pressure is high enough. Past a certain combination of heat and pressure you hit the supercritical point of the mixture and this changes the reactivity most dramatically in some cases.

Please could you be a little clearer as to what you want out of the replies to this post?
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #2 on: April 13, 2014, 04:54:17 PM »
I would want help with the questions including figuring out the molarity of the compounds at each step of this reaction with methane and chlorine.

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Free Radical REaction
« Reply #3 on: April 13, 2014, 05:02:55 PM »
Archer give you a little hint that at least some of your basic premises are simply wrong.  You've written a giant thread of incorrect assumptions and fabricated chemistry.  Its hard to know where to begin to help you.  Your statement that only liquids react is simply wrong.  And its going to be practically impossible to have cryogenic liquids and molten boron and phosphorous in the same reaction vessel.  Your units are also wrong -- the understood units of a chemical reaction are moles, not molarity.  And just because you've written a reaction, doesn't mean it will happen.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #4 on: April 13, 2014, 07:10:34 PM »
I know the units are moles but I am shortening it by saying Molarity instead of moles/liter. 2 M is the same thing as 2 moles/liter.

I am not saying that only liquids react. I am just saying that liquid is the optimal state of reaction.

I know that this will happen because chlorine reacts with just about anything.

Now the most likely form of phosphorus I will use is phosphate. That is cryogenic because of all the oxygens. That will give me phosphorus and oxygen for forming things with phosphorus and forming things with oxygen.

I am wanting to use STP because that is the easiest to use. I am also not wanting aqueous because a lot of it is nonpolar.

Thus my reasoning towards liquids.

As far as what to use I am starting with Chlorine and seeing what forms, than siphoning the alkanes, alkenes, and alkynes into separate vessels where I put the oxygen. After that I look at what forms and what doesn't for the oxygen and siphon a specific type of compound with oxygen into a vessel and do that for all the oxygen compounds and same goes for nitrogen, boron, and phosphorus.


So my heriarchy of siphoning and reacting is this:
Initial reactions :rarrow: Alkenes, Alkynes, Alkanes in separate vessels reacting with oxygen  :rarrow: Separate types of oxygen compounds reacting with nitrogen in separate vessels  :rarrow: Separate types of nitrogen compounds reacting in separate vessels with phosphorus  :rarrow: Separate types of phosphorus compounds reacting with boron in separate vessels
and so it is like a tree of reactions with the most being siphoned at the oxygen, than less with nitrogen than less with phosphorus, than less with boron sort of like an upside down binary tree

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #5 on: April 13, 2014, 10:49:54 PM »
This is not how you go about making these compounds.

Liquid oxygen reacts uncontrollably with most oxidisable substances.
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #6 on: April 13, 2014, 11:03:09 PM »
well than how would I make those types of oxygen compounds from alkanes, alkenes, and alkynes if I can't just put in liquid oxygen? It would seem that the double bond in the oxygen lowers the reactivity because the oxygen has its octet and that slight bonds between the oxygen molecules that act like hydrogen bonds would lower it even more. I mean chlorine will react uncontrollably but that's because it is a halogen and all halogens react that way.

I understand that oxygen can oxidize things but in chemistry oxidise just means lose oxygen. Thats how come you hear about oxidation by hydrogen, oxidation by carbon, and oxidation by oxygen.

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #7 on: April 13, 2014, 11:10:23 PM »
Oxidation is loss of electrons, not loss of oxygen.

There are many selective oxidising reagents which can be employed in forming said compounds.

“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #8 on: April 13, 2014, 11:15:51 PM »
yes I meant electrons instead of oxygen.

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #9 on: April 14, 2014, 03:07:10 PM »
I would really like to help you here but I am confused as to what you want.

Are you trying to demonstrate that, theoretically any chemical can be made starting from methane and elemental Chlorine?
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #10 on: April 14, 2014, 03:36:18 PM »
I am trying to demonstrate that theoretically any chemical can be made starting with methane and any halogens single or combined yes.

I am demonstrating it with chlorine to start off with since it is the most common one

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #11 on: April 14, 2014, 04:28:02 PM »
I am trying to demonstrate that theoretically any chemical can be made starting with methane and any halogens single or combined yes.

I am demonstrating it with chlorine to start off with since it is the most common one

Is there any particular reason why, are you planning to attempt this or is it just idle curiosity?
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #12 on: April 14, 2014, 04:39:15 PM »
It is curiosity.

Offline Archer

  • Chemist
  • Sr. Member
  • *
  • Posts: 1001
  • Mole Snacks: +85/-20
  • Gender: Male
Re: Free Radical REaction
« Reply #13 on: April 14, 2014, 04:54:09 PM »
In principal you could make any organic compound from methane and chlorine as your starting material but not in the way you have described.

Primarily the reaction of Cl2 and methane is a radical reaction which requires irradiation to initiate. If you want your next step to be disproportionation to ethane and chorine then your chlorine concentration would have to be incredibly low and the reaction carried out in the gas phase.

Once you have isolated methylchloride, in principal, you can do many functional group interconvertions, chain lengthening, shortening, cyclysation etc. this would have to be carried out in a controlled manner.

You may find biosynthesis a fascinating topic. Plants can do more with CO2, H2O and NOx than any chemist could do with all the modern resources around today.
“ I love him. He's hops. He's barley. He's protein. He's a meal. ”

Denis Leary.

Offline caters

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +1/-6
Re: Free Radical REaction
« Reply #14 on: April 25, 2014, 04:49:43 PM »
But I have always thought that no matter the reaction liquid is optimal because solids don't react unless it is oxidation or dissolving and gases have little time to react because they move so fast.

Plus standard pressure is I think best if you want to carry this out in the liquid state because pressure often increases temperature if you add it and decreases if you subtract it so the reactants at low pressure, almost a vacuum will be solid but at high pressure be a gas. Temp is much easier to change without affecting pressure than pressure is without affecting temp.

That is why liquid at standard pressure is optimal for reactions.

As for starting the reaction liquid chlorine could just touch a methane molecule that is also liquid and grab that hydrogen and the other chlorine bonding to the methyl that is left without irradiation because liquids more often touch the right way than gases do.

Sponsored Links