Translate

Search This Blog

Saturday, 13 September 2014

Limit Test for Sulphates

 All solutions used for this test must be prepared with distilled water R.
 
 Add 3 ml of a 250g/l solution of barium chloride R to 4.5ml of sulphate standard  solution (10ppm SO4)R1. Shake and allow to stand for 1 min. To 2.5 ml of this  solution, add 15ml of the solution to be examined and 0.5ml of acetic acid R.  Prepare
a standard in the same manner using 15ml of sulphate standard solution (10ppm SO4) R instead of the solution to be examined.
 
 After 5min, any opalescence in the test solution is not more intense than that in the  standard.  

Reagent used
§  250 g/l solution of barium chloride
§  Acetic Acid: Dilute 30g of glacial acetic acid to100ml  with water. It contains not less than 29.0% and not more than 31.0% w/v of C2H4O2 (5M).
§  Sulphate Standard Solution (10ppm SO4) R1:  Dilute 1volume of a 0.181% w/v solution of potassium sulphate in ethanol (30%) to 100 volumes with ethanol  (30%).








No comments:

Post a Comment