Sodium Acetate

Using Sodium Base

Sodium acetate is a very useful compound if you ever need the acetate ion (CH3COO-). It is used for making Acetic acid, Acetyl Chloride, and Acetic Anhydride (along with some others). It can also be used for the super saturated solutions chemistry demonstrations. Sodium acetate is generally made by neutralizing vinegar with a sodium base. In this synthesis, both sodium hydroxide and sodium bicarbonate will be shown.

The reaction proceeds as follows:

CH3COOH + NaOH ----> CH3COONa + H2O

Or:

CH3COOH + NaHCO3 ----> CH3COONa + H2O + CO2

This means that for every mole of acetic acid, we need 1 mole of sodium hydroxide or 1 mole of sodium bicarbonate. One mole of 5% vinegar is equal to 1201grams which is equal to 1189mls (Using 1.01g/cm3 density)

Materials	Equipment
Vinegar (5%)	1000ml flask of any kind with a fitting stopper
Sodium Hydroxide or sodium bicarbonate	Red and Blue Litmus papers
	200ml Evaporating dish
	600ml beaker
	Alcohol burner (recomended, but optional)

Synthesis:

Measure out 405mls of vinegar and pour it into a 1000ml flask. Weigh out 13 grams of sodium hydroxide or 29 grams of sodium bicarbonate. Add the sodium hydroxide or bicarbonate to the flask in small portions, say 3 grams at a time and swirl until its all dissolved. After every two portions added, swirl the flask. Once all the hydroxide or bicarbonate has been added, swirl it well. Take a small sample of the the solution and place 1 drop on a strip of red litmus and 1 drop on a strip of blue litmus. If the red shows any base present, add more vinegar (5ml at a time) and swirl until it shows none. Remember, it is always better to have more acid than base as the acid can just boil away. The base can not. If you have just a trace ammount of pink on the blue litmus, that is perfect. Place the solution into a 600ml beaker and boil it away until its down to the 100ml mark on the beaker. While its still hot, pour the solution into the 200ml evaporating dish. Heat it over an alcohol flame (don't let the flame touch the bottom of the dish) for a while (stirring it often) until there is no visable water left in the bottom of the dish. Do not leave or the sodium acetate will burn or get stuck to the bottom of the evap dish. After this, place the evaporating dish in an oven at 105C (225F) for about 3 hours (Always open the oven and stir it if it turns into a liquid. One of the most annoying things is getting a solid baked into your evaporating dish). After the 3 hours is up and its clearly a solid, crank the heat up to 200C (395F) for 1 hour. You will be left with anhydrous sodium acetate. The theoretical yeild is 28grams but you should get ~25 grams with this procedure if you are careful.