Sciencemadness Discussion Board

Wet ether

Jacob - 20-6-2019 at 02:02

I added 0.5g of K to 30cc of my old Et2O. It kept fizzling for 15 minutes, with an intensity between coke and effervescent tablets.

Is it done for? Should I get some new ether? Or should I dry it with a sulfate?

No UTFSE results.

DrP - 20-6-2019 at 02:19

Was your 1/2 gram K stretched into a wire or a single lump?

Reduced pressure distillation at low temp? Then leave the K wire in it over night?

vmelkon - 21-6-2019 at 07:00

Maybe your diethyl ether was boiling due to the heat of the reaction.

zed - 21-6-2019 at 15:01

Yeah. K would be a final drying agent.

Wet ether that is really wet, needs preliminary drying with other agents.

Alkali metals in wet ether, develop a protective coating pretty quickly.

Use the search engine. Should be lots of entries on drying ether.

Most of us, at one time or another, have struggled with it.

[Edited on 21-6-2019 by zed]

UC235 - 21-6-2019 at 16:34

I would probably rough-dry ether with anhydrous MgSO4, then use something like powdered Na-Pb alloy to do a final drying.

draculic acid69 - 21-6-2019 at 23:03

Did you check for peroxides first you know being old ether and all.might explain the fizzing

Metacelsus - 22-6-2019 at 04:59

Quote: Originally posted by UC235  
I would probably rough-dry ether with anhydrous MgSO4, then use something like powdered Na-Pb alloy to do a final drying.

I would suggest distillation from Na/benzophenone instead of Na-Pb.

OP, what are you planning to use the ether for? MgSO4 drying might be enough for some reactions.

[Edited on 2019-6-22 by Metacelsus]

fusso - 22-6-2019 at 05:08

Why is benzophenone used?

BromicAcid - 22-6-2019 at 06:17

It's reduced with potassium to the diphenylketyl anion. Thisl is soluble in ether. This lets the drying agent go into solution so it's homogenous drying instead of heterogenous drying which is less effective/takes more time.

[Edited on 6/22/2019 by BromicAcid]

Mabus - 4-9-2019 at 09:31

Jacob, did you ether changed color after the reaction?
I had a similar issue a while ago with some ether from car starting fluid. Turns out, the said ether had lots of acetaldehyde, which came from the manufacturing process.

Sturge11 - 5-9-2019 at 22:17

Saw someone suggest dry epsom salts, aka dehydrated MgSO4. I would attempt this first.

Amos - 6-9-2019 at 10:22

Always use your least expensive drying agent first if you have no idea what the moisture content is. I'd let a small volume like that sit over an anhydrous salt overnight then go with sieves or alkali metal. Bigger volumes I just reflux under a soxhlet full of sieves a few times.

Jacob - 7-10-2019 at 07:13

Thanks all! I reacted it with sodium and dried it with NaOH then distilled. As good as new. The idiots that used it before me confessed that it might contain acetone.