Glacial acetic acid

Acetic acid or ethanoic acid is a useful compound with many applications in the home lab. Glacial acetic acid is the name given to 100% anhydrous (water free) acetic acid, this is not the same thing as white vinegar which is 5% acetic acid.  I had a go at making some good glacial stuff a while ago:

I started by pouring around 90g sodium bisulphate into a round bottom flask. I then poured about half its volume of anhydrous sodium acetate into the flask. (The molar ratios aren't really important as the sodium bisulphate should be in excess). Next I attached an adaptor to the flask and a condenser and set up for simple distillation.

At around 60 C the sodium bisulphate began to melt and react. At about 90 C acetic acid was observed refluxing in the flask. At 100-110 C the acetic acid began to distil over and was collected. Once the acetic acid stopped coming over the distillation was stopped.

The distillate collecting had an extremely strong vinegary smell. I poured a small amount of the product into a test tube and added a bit of sodium bicarbonate. Very little reaction was observed showing that the acid was close to glacial. Dilute acetic acid reacts much more violently with sodium bicarbonate than glacial acetic acid does. This was the result of my work:

NaHSO4 + NaCH3COO ==> CH3COOH + Na2SO4

The sodium acetate and sodium bisulphate were very poorly mixed and ground up. This is probably why my yield was so low. Next time I try this I'll make sure they're ground and mixed together thoroughly.