Author Topic: Sodium acetate synth...  (Read 1628 times)

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zooligan

  • Guest
Sodium acetate synth...
« on: January 08, 2001, 04:10:00 PM »
...using vinegar and lye?

I believe there used to be one on the UBB boards, but I can't find it there or at Rhod's site.  Anyone have this text or know the reaction details?

z

uemura

  • Guest
Re: Sodium acetate synth...
« Reply #1 on: January 08, 2001, 04:35:00 PM »
vinegar and lye?

Yes, it's that easy! Just take a bit more vinegar than lye and then boil down the solution up to the point a drop on a glasrod from the solution cristallises.

If you need anhydrous Na-acetate then heat the salt using a small flame in a porcelain pot up it melts and becomes dark. This makes all water to disappear. Pour it hot in a wide neck bottle, close it and let cool.

zooligan

  • Guest
Re: Sodium acetate synth...
« Reply #2 on: January 08, 2001, 07:55:00 PM »
Well shit!  It doesn't get much easier than that.   8)  Now, what would one use to re-crystallize the salt and clean it up a bit, or is this not needed?

z

zooligan

  • Guest
Re: Sodium acetate synth...
« Reply #3 on: January 08, 2001, 08:07:00 PM »
BTW, what is the % concentration of normal supermarket vinegar?  What is the max % it can be concentrated to with kitchen lab equipment?

z

Rhodium

  • Guest
Re: Sodium acetate synth...
« Reply #4 on: January 09, 2001, 12:03:00 AM »
Just neutralize vinegar (usually 19-24%) with 25% sodium hydroxide (lye) solution and evaporate the excess water until the sodium acetate trihydrate crystallizes. A much better way of making the salt anhydrous is to nuke it in a pyrex pan in the microwave until no more water vapor is given off and the large translucent trihydrate crystals has been converted into a dry amorphous powder.


http://rhodium.lycaeum.org


terbium

  • Guest
Re: Sodium acetate synth...
« Reply #5 on: January 09, 2001, 03:49:00 AM »

vinegar (usually 19-24%)


Wow! Remind me never to put straight vinegar on my salad in what ever country you live in. Vinegar around where I live is 5% acetic acid.


uemura

  • Guest
Re: Sodium acetate synth...
« Reply #6 on: January 09, 2001, 07:10:00 AM »
In Europe you can find 'vinegar essence', which is 25% acetic acid. It is diluted before you put it on your salad!

uemura

  • Guest
Re: Sodium acetate synth...
« Reply #7 on: January 09, 2001, 07:15:00 AM »
Gourmets of course won't use pure acetic acid! They prefer Aceto Balsemico for the salad, which, however is useless for the preparation of Na-acetate!

Pheesees

  • Guest
Re: Sodium acetate synth...
« Reply #8 on: January 10, 2001, 03:58:00 AM »
Pickling vinegar is double the strength of the regular stuff.


Drug related....god, I love my relatives!

Chromic

  • Guest
Does not work
« Reply #9 on: November 22, 2002, 01:43:00 AM »
This does not work with regular vinegar. Regular vinegar contains a number of organics as it has not been distilled. If you do this, your sodium acetate will turn out dark brown. Make sure to get the vinegar essence or to distill you vinegar first. The best way is with baking soda and distilled vinegar. The bubbles are entertaining.  :)

lugh

  • Guest
Commercial Process
« Reply #10 on: November 22, 2002, 02:56:00 AM »
The commercial process for preparing glacial acetic acid is to neutalize the hydrated acetic acid with sodium carbonate, recrystallizing the sodium acetate, then fusing it to expel the water of crystallization. It is then distilled with concentrated sulfuric acid to obtain glacial acetic acid  :)

Rhodium

  • Guest
Sodium acetate and ethanol from ethyl acetate/lye
« Reply #11 on: November 22, 2002, 03:46:00 AM »
In the beginning of my career as a chemist, I couldn't buy 96% ethanol anywhere, and distilling technical ethanol or vodka didn't give a result pure enough for my liking, so I bought lots of OTC ethyl acetate, and hydrolyzed it with a strong lye solution, followed by distilling off the formed ethanol. Allowing the water to evaporate from the residual solution gave large amounts of sodium acetate trihydrate, which crystallized in large shards. Microwaving these shards until no more water vapor was given off left a dry amorphous powder of anhydrous sodium acetate. I still have several kilos of both the hydrated and the anhydrous form stowed away since that time, I have a serious problem throwing things away even if I know I don't need it...  ;)

Aurelius

  • Guest
Kilos
« Reply #12 on: November 22, 2002, 06:23:00 AM »
oh come on Rhodium, with all the NaAc catalyzed reactions and such- and you can't find a use?

Rhodium

  • Guest
Its also a question of scale...
« Reply #13 on: November 22, 2002, 06:27:00 AM »
I have used at most a few hundred grams over the past five years... I don't need two buckets...  ;)

Chromic

  • Guest
Commercial process
« Reply #14 on: November 22, 2002, 06:28:00 AM »
I have some sodium acetate that was laborously made by neutralizing distilled vinegar with baking soda so that's no trouble there (using a small excess of acetic acid, boiling down and drying). Can you suggest how much conc sulfuric acid should be added per gram of sodium acetate? Are we talking a small excess of sulfuric acid or a healthy excess?

I do wish to appologize about pulling up so many threads from across the board. I was pissed off that there wasn't good information in any of them and thus made sure to contibute information to each thread. I'm glad they're all referencing this post where hopefully I'll give some detailed instructions.

Organikum, thank you for some of the details, I will try a freeze separation as well. I hope it will give GAA, but for some reason, I highly doubt it. Any time I've tried to freeze purify alcohol from water, it's never worked very well... I don't see why this would be any different, the acetic acid is going to be highly hydrogen bonded. Mind you... I have to say that freeze purifying anethole and safrole works spendidly!

in

Post 382036

(Organikum: "distilling, than freezing out", Chemicals & Equipment)
you say to distill to 95% then freeze out the rest of the water. Well, the trouble is, in

Post 382006

(Chromic: "Drying acetic acid", Chemicals & Equipment)
, I show how you need a huge amount of theoretical places to be able to purify the acetic acid.

As I said, I used a 500mm fractionating column going as slowly as possible and got piss-poor results. I'm sure if I had a 50m column I could do this, but I have't yet turned my house into a chemical plant. It appears that you can't distill a substancial amount of acetic acid to a decent purity, ie 90+%.

I will try the freezing method though, can't hurt to give it a shot. I'd also love to hear how little H2SO4 I can get away with using to distill GAA from the mix. I know 59.7g H2SO4 per 100g NaOAc is what theory says, but because 86.6g of Na2SO4 would be produced, it appears that without a doubt you'd have to use more H2SO4.