7. PROCEDURE
Solubility test
7.1.1 Carry out a solubility test on the sample in water at room temperature in the proportion of 2 g per 100 ml.
Preparation of the solution
7.1.2 Weigh to the nearest 0.001 g, according to the indications in the Table, a quantity of 5, 7 or 10 g of the prepared sample and place it in a 500 ml graduated flask. From the result of the solubility test, proceed as follows:
(a) Products completely soluble in water
(a)Add to the flask the quantity of water needed to dissolve the sample; shake, and when completely dissolved, make up the volume and mix thoroughly.
(b) Products not completely soluble in water
(b)Add to the flask 50 ml water and then 20 ml hydrochloric acid solution (4.1). Shake and leave undisturbed until the evolution of carbon dioxide has ceased. Add 400 ml water and shake for half an hour with the rotary shaker (5.2). Make up to volume with water, mix and filter through a dry filter into a dry receiver.