WHAT IS THE WATER USED FOR? acetic anhydride and 2-hydroxy benzoic acid mechanism?

Question

The laboratory procedure is as follows:

Mix 2 grams of salicylic acid with 4 milliliters of acetic anhydride in a 125 milliliter Erlenmeyer flask.
Add 3 or 4 drops of concentrated sulfuric acid to the flask and stir.
This is an exothermic reaction and so heat will be liberated when the reaction starts. If the flask does not warm, add another drop of acid to the flask until the heating effect begins.
Once the heating effect is detected, heat the reaction mixture in a water bath at 50 degrees centigrade for 5 minutes in order to drive the reaction to completion.
Cool the flask and then ADD 40 MILLILITRES OF WATER. Stir the aqueous mixture until a solid is formed and becomes well dispersed in the liquid.
Filter the liquid by suction using a Hirsch funnel and wash with cold water.
Use hot water to crystallize the filtrate.
If necessary use carbon to decolorize.
WHAT IS THE WATER USED FOR?

Answer 1

The previous answer is partially correct.

Water reacts with the excess acetic anhydride which is converted to acetic acid.

Since the product is only slightly soluble in water, this also makes it possible to collect the product as a solid.

Answer 2

The water is first added to react with the excess acetic anhydride. Water will react with that to form acetic anhydride. The aspirin that you're making is only slightly soluble in cold water. So the water also makes the aspirin product preciptate so you can collect it.

Answer 3

water will convert the residual acetic anhydride into acetic acid.