Inorganic Chemistry lacture - 4 “Limit test: Principles, Examples & Easy Explanation”
π§ Introduction Limit tests are semi-quantitative tests used to check whether the amount of impurity in a substance is within permissible limits or not . π These tests are very important for drug safety and quality control . ⚙️ What is the Principle of Limit Test? π Based on comparison method π Test solution is compared with a standard solution ✔ If test ≤ standard → Pass ✔ If test > standard → Fail π§ͺ Limit Test for Chloride π¬ Principle: Chloride ions react with silver nitrate (AgNO₃) to form silver chloride (AgCl) (white turbidity). π Turbidity of test solution is compared with standard. π§ͺ Limit Test for Sulphate π¬ Principle: Sulphate ions react with barium chloride (BaCl₂) to form barium sulphate (BaSO₄) (white turbidity). π Compared with standard solution. π§ͺ Limit Test for Iron π¬ Principle: Iron reacts with thioglycolic acid → forms purple colored complex . π Color intensity is compared with standard. π§ͺ Limit Test for Arsenic π¬ Principle: Arsenic → conve...