7. Test for Soluble Salts (..contd)
b) Determination of Sulphate
The clay to be tested has to be taken out from the bulk supply by ‘Cone and Quarter’ method - the sample to be prepared is around 1 kg. From this master sample take out about 100 gms and soak it in distilled water about 1 litre. After soaking, stir it for few minutes and leave the sample overnight.
- Pipette out 100 ml of sample solution into a beaker.
- Boil and add 10 ml of 10% solution of Barium Chloride.
- Allow the Barium Sulphate precipitate formed overnight.
- Filter the precipitate through filter paper by washing it thoroughly with boiled water.
- Ignite the precipitate, cool and weigh, express as sulphate.
