Hello,

I am trying to produce sodium acetate for the popular supersaturated recrystallization demo. I have added an equimolar amount of bicarb to white distilled vinegar and boiled that away, but all I get is a light brown, clunky powder, mixed with a bit of white throughout.

I have found that the product is a little less brown if I boil it a bit more gently, but I have also tried evaporating the solution instead of boiling, only to still receive the same mysterious brown powder. The brown powder is soluble in water, forming a dirty chocolate brown solution. I have also tried neutralizing with NaOH instead, only to receive the same result. Thinking impurities, I have tried two store bought brands of vinegar with no difference in result.

This reaction is well-known and should be pretty straightforward. Where am I going wrong?

I recall reading:

Sodium Acetate can be prepared by adding an equimolar amount of sodium hydroxide to glacial acetic acid.

Sodium Hydroxide is available for biodiesel/soap production and glacial acetic acid is available as a photography chemical. In doing this with only pure compounds, you avoid the nuisance of using "grocery" chemicals, which often (like woelen said) have extra things in them.

Hope that helps?

.rayfe-

Try making sure the bottle says distilled vinegar. That is bound to have fewer impurities. I'm actually not really sure what companies mean by sticking the distilled word on the bottle. I've assumed it to mean that it's glacial acetic acid diluted with deionized water, but I think that's a little hopeful.

If you can try to purchase glacial acetic acid (caution it hurts to get on you, a lot) and NaOH from a chemical supplier.