Earlier I tried to make some sodium acetate for acetic acid preparation, but the end product was a yellowish mush instead of white/clear crystals. I
used household vinegar for the acetic acid and ordinary baking soda for the sodium bicarbonate. Luckily I took a video:
IIRC most vinegar is made from the fermentation of grain ethanol, which involves the dilution of conc ethanol addition of microbial nutritents and
acetobacter. My guess is the dark colored impurities are a result of that process. You could try stirring you brown solution with activated carbon for
a while then filter through diatamaceous earth. Or if you are simply going to distill your acetate with sulfuric acid it may not be worth the trouble.achem500 - 30-7-2012 at 15:54
Thanks
making NaOAc trihydrate from scratch
quantumchromodynamics - 26-1-2014 at 01:44
I started with a box of baking soda in a crock pot set to warm.
Every day I added a few cups of vinegar, stirred the fizz down, and tested pH.
With the crock pot on warm about half the volume of liquid was reduced away each day.
Almost 4 gallons of vinegar later! the pH is neutral, with about 2L of yellowish grainy product.
Trying to crystallize, I heat the product into a yellowish liquid and filter into a big beaker.
I let the beaker cool and initiate precipitation with seed crystals.
This works but,
There is too much H2O in the product.
The bottom is NaOAc trihydrate, but the top remains a slurry.
There is not a clear phase boundary.
How can I get the amount of H2O right?
I observe the boiling point NaOAc trihydrate is 122C > 100C.
When I boil at lowest possible stove setting hoping to boil away the H2O, and leave behind the NaOAc , the vapor contains NaOAc! The steamy sides of
the beaker taste like vinegar, the kitchen gets way to pungent, and when I cool off the beaker a white powder forms on the sides.
I assume the yellow color is from impurities. I would like to make nice clean NaOAc trihydrate. Can someone suggest a process to clean impure NaOAc
trihydrate? macckone - 26-1-2014 at 10:08
One method of purification is carbonizing at 280C.
The impurities will mostly be converted to carbon.
The relevant patent: http://www.google.com/patents/US1857520
What the hell? Please, this is a "BEGINNINGS" post.
This patent is a bit beyond my addled brain.
A bit of crud in my vinegar and now I have to understand US1857520 and buy equipment to "carbonize" at 280C? Please tell me it isn't so!
achem500: The youtube video isn't there anymore.
well, not the best but...
quantumchromodynamics - 29-1-2014 at 04:21
Turns out that blowing a jet of warm air into the crock pot eventually reduced the top layer of sludge. This method seemed to evaporate just the
water, leaving the sodium acetate behind. I don't know why sublimation seems tow work, but low temperature boiling does not work. Still unable to
remove the yellow tinge from the crystals. Carbonization at 280C is not a good option for me. I will try some activated charcoal adsorption as soon as
my e-bay charcoal gets here. Since we like pics, here is my nice big bowl full of product.
[Edited on 29-1-2014 by quantumchromodynamics]
Zyklon-A - 29-1-2014 at 06:47
A little off topic, but my vinegar says that it's distilled, which would remove sugars and whatever else is in there right? Or do they add the sugar
for flavor?subsecret - 29-1-2014 at 07:33
I actually found a product known as "cleaning vinegar" at my local hardware store. According to the list on the label, acetic acid and water are the
only ingredients. Sorry, I was unable to find an MSDS for this product, but it looks promising for lab use.Zyklon-A - 29-1-2014 at 08:27
In a video on youtube, on geting lab chemicals, I saw someone mention such a thing. I'll get it next time I go to a hardware store.macckone - 29-1-2014 at 10:33
Carbonization at 280C is not a good option for me. I will try some activated charcoal adsorption as soon as my e-bay charcoal gets here.
Simply put it in the oven in a covered container at the maximum
heat setting. That should get you close enough to carbonize
most of the impurities. Of course you still need to dissolve, filter,
recrystallize to get rid of the carbon.Sedit - 29-1-2014 at 14:42
Crush and wash with acetone if its so big of an issue.
