Sciencemadness Discussion Board

Ethylene oxide and Acetaldehyde

Etidorpha - 30-12-2003 at 11:11

Now, I do know that I can add H2O2 to ethanol and I get a highly volatile distillate with a boiling point in the range of either ethylene oxide or the acetaldehyde. It is quite a nice reaction and can be done easily with CO2(s)/acetone cooling, though I suppose salt water/ice would work as well. It works similar to the nitric acid/ethanol reaction which is done in much the same way. I am wondering however which compound I am finding in my receiver.

Ah, one other question while I have your attention. When I have acetaldehyde, and react it with, say, silver chloride, and take the solution to dryness, I have a liquid silver compound remaining that I have not been able to identify.

CH2CH2O + AgCl ---> ???

DDTea - 30-12-2003 at 13:23

At room temperature, Ethylene Oxide is not a volatile liquid, but a gas (and also poisonous and dangerously explosive!). Chances are, by adding an oxidizer to a primary alcohol, you have Acetaldehyde. If the H2O2 is concentrated enough, you might have made Acetic Acid, as oxidation of an aldehyde produces a Carboxylic Acid. Chances are, it's a combination of these two chemicals.

C2H5OH + O --> C2H4O + H2O

C2H5OH + O2 --> C2H4O2 + H2O

Geomancer - 31-12-2003 at 09:37

Both of your hypothetical products are quite reactive, but in different ways. You can use this fact to find out what you have. What reactions are characteristic of epoxides? Aldehydes? What would happen if you reacted each with a small portion of dilute HCl?

KABOOOM(pyrojustforfun) - 2-1-2004 at 13:34

there are a wide variety of reagents u can use to test aldehydes I won't get involved. the easiest test I can think of for acetaldehyde is to add some NaOH to the solution it should turn yellow if it is acetaldehyde (formation of aldol) if u use too much NaOH you'll get a yellow aldehyde resin (read vogel for more aldehyde tests)

unionised - 3-1-2004 at 08:07

Could you tell us more about the liquid silver compound please? Most silver compounds are insoluble and high melting.

Aldehyde Test

Acid Test - 6-1-2004 at 16:09

Quote:
The surefire test of any aldehyde(except for benzaldehyde...DUH) is to dissolve 10 mg in water and ingest it.Since aldehydes are sedative/hypnotics(and are a schedule I controlled substance in the states) they should sedate you.l
If this doesn't sedate you but doesn't kill you raise the dose to 20 mg.If you reach 100 mg and don't get anything(after ingesting a total of 690 mg in a period of 5 -10 hours then you probably don't have aldehyde

For your equation I don't think it would act on its own until about 10 years has passed without a catalyst,unless the AgCl is the catalyst for ketone hydrogenation!?!

CH2CH2O + AgCl ---> ???

I don't think I'll try that.

Etidorpha - 7-1-2004 at 05:25

No, I don't think I will be drinking the volatile stuff. That seems kind of a silly way to test a compound. But the silver thing is interesting, too. You may wish to try it. I don't know what the result is, though.

Acid Test - 8-1-2004 at 06:28

Quote:
Originally posted by Etidorpha
No, I don't think I will be drinking the volatile stuff. That seems kind of a silly way to test a compound. But the silver thing is interesting, too. You may wish to try it. I don't know what the result is, though.


The silver formula is Etidorpha's idea

chemoleo - 8-1-2004 at 07:40

Hmm, liquid silver? or do you mean the deposition of silver, aka the formation of a silver mirror on the tube? I think this is one of the standard tests to detect aldehydes, whereby the aldehyde (or aldo-sugars) is oxidised to acid, while the Ag+ is reduced to Ag (s). If conditions are done correctly one finds such silver deposits.
Also, I seem to remember that acetaldehyde forms an adduct with HSO3- IIRC, which is reversible. This is a crystalline substance. Alternatively, it also reacts with ammonia. I dont have the detailed info at hand right now, but you should be able to find more in any org. chem. textbook.

Purple Haze - 9-1-2004 at 08:29

You can also reverse the aldehyde back to an
alcohol.All alcohols basiclly smell the same
before thier conversion.There would probably
be a residue of the reaction which you may
want to filter

unionised - 10-1-2004 at 06:34

Not all aldehydes are noticably sedative.
(for example the aldehyde under discussion, acetaldehyde, is used as a flavouring agent.)
Alcohols don't all smell the same. Linalool smells of lilly of the valley. tButanol smells like camphor.
Aldehydes will generally reduce silver salts in solution in dilute ammonia to produce silver, ethylene oxide won't. OTOH it's very unlikely you got this.