S.L. 437.69 ст. 5the sample as expressed as expressed as fitted with acid (3.1), and the tube (1) with coloured level of the (1) and (3) tilting the flask (4) until (1) and (2). the reading. (3.2). 6. The content percentage of where: V = ml of T = ml of W = weight, 7. 7.1. When distilled water volume of 7.2. If the

PROCEDURE According to the sample's carbonate content, weigh a portion of shown below: 0ꞏ5 g for products containing from 50 to 100% of carbonates, calcium carbonate; 1 g for products containing from 40 to 50% of carbonates, calcium carbonate; 2 to 3 g for other products.

Place the portion of the sample in the special flask (4) of the apparatus, a small tube of unbreakable material containing 10 ml of hydrochloric connect the flask to the apparatus. Turn the three-way cock (5) so that connects with the outside. Using the mobile tube (2), which is filled sulphuric acid (3.3) and connected to the graduated tube (1), bring the liquid up to the zero mark. Turn the cock (5) in order to connect up tubes and check that the level is at zero. Run the hydrochloric acid (3.1) slowly over the portion of the sample, flask (4). Make the pressure equal by lowering the tube (2). Shake the the release of carbon dioxide has stopped completely.

Restore pressure by bringing the liquid back to the same level in tubes After a when the volume of gas has become constant, take few minutes, Carry out a control test in the same conditions on 0ꞏ5 g of calcium carbonate CALCULATION OF RESULTS

in grammes of carbonates, expressed as calcium carbonate, as a the sample, is calculated by using the formula:

V x 100 T x 2W

CO released by the portion of the sample. 2 CO released by 0ꞏ5 g of CaCO A.R. 2 3 in grammes, of the portion of the sample. OBSERVATIONS the portion of the sample weighs more than 2 g, first place 15 ml of in the flask (4) and mix before beginning the test. Use the same water for the control test. apparatus used has a different volume from that of the Scheibler-apparatus, the portions taken from the sample and from the control the calculation of the results must be adapted accordingly.