Hello aspirant,

Limit test is defined as quantitative or semi-quantitative test that is designed to control and identify small amounts of impurity that is likely to be present in the substance. It is generally carried out so as to determine the inorganic impurities present in the compound.

Barium sulphate reagent: • 0.05 M Barium chloride solution is prepared by dissolving 12 g of barium chloride in 1000ml of water, to the 15 ml of the above solution add 55 ml of water, 20 ml of alcohol and 5ml of 0.0181% w/v solution of potassium sulphate and the final volume was made up to 100 ml.

Hope, this answer helps you.