Limit Test of Chlorides – Pharmaceutical Inorganic Chemistry Practical Get link Facebook X Pinterest Email Other Apps August 29, 2025 🎯 Aim To perform the Limit Test for Chlorides as per Indian Pharmacopoeia standards and compare the sample with a standard solution using a Nessler cylinder. 📖 Principle The Limit Test for Chlorides is a semi-quantitative test designed to detect traces of chloride impurities in inorganic substances. When chlorides react with silver nitrate in the presence of dilute nitric acid, a white turbidity of silver chloride is produced. The turbidity in the test solution is compared with that in a standard chloride solution using Nessler cylinders placed side by side against a black background. 👉 If the turbidity of the test solution is not greater than the standard, the sample passes the test. 🧴 Chemicals & Reagents Required Test sample solution Dilute Nitric Acid (HNO₃) Silver Nitrate solution (AgNO₃, 0.1N) Standard Sodium Chloride solution (NaCl, 0.02% w/v) Distilled water ⚗️ Apparatus Nessler Cylinders (2 pieces) Pipettes Beakers Glass rod 🔬 Procedure Test Solution Preparation Dissolve the given sample in water and add 5 mL of dilute HNO₃. Dilute to 50 mL with distilled water in a Nessler cylinder. Standard Solution Preparation Take 1 mL of 0.02% NaCl solution in another Nessler cylinder. Add 5 mL of dilute HNO₃ and make up to 50 mL with distilled water. Reaction To both cylinders, add 1 mL of 0.1N AgNO₃ solution. Mix well and allow to stand for 5 minutes. Observation View both cylinders against a black background. Compare the turbidity of the test solution with the standard solution. ⚛️ Chemical Reaction AgNO3+Cl−→AgCl↓(Whiteprecipitate)AgNO₃ + Cl⁻ → AgCl ↓ (White precipitate) AgNO3+Cl−→AgCl↓ (White precipitate) The white turbidity is due to the formation of silver chloride (AgCl). 📊 Observation Table SolutionObservation (Turbidity)Test Solution__________Standard Solution__________ ✅ Result If the turbidity of the test solution ≤ standard solution, the sample passes the limit test for chlorides. If the turbidity is more, the sample fails the test. ✍️ Viva Questions (for Students) What is the principle of the limit test of chlorides? Why is nitric acid added in this test? What is the role of AgNO₃? What is the appearance of the precipitate formed? 👉 Download full PDF of Limit Test of Chlorides Practical [here] Get link Facebook X Pinterest Email Other Apps Comments
🎯 Aim To perform the Limit Test for Chlorides as per Indian Pharmacopoeia standards and compare the sample with a standard solution using a Nessler cylinder. 📖 Principle The Limit Test for Chlorides is a semi-quantitative test designed to detect traces of chloride impurities in inorganic substances. When chlorides react with silver nitrate in the presence of dilute nitric acid, a white turbidity of silver chloride is produced. The turbidity in the test solution is compared with that in a standard chloride solution using Nessler cylinders placed side by side against a black background. 👉 If the turbidity of the test solution is not greater than the standard, the sample passes the test. 🧴 Chemicals & Reagents Required Test sample solution Dilute Nitric Acid (HNO₃) Silver Nitrate solution (AgNO₃, 0.1N) Standard Sodium Chloride solution (NaCl, 0.02% w/v) Distilled water ⚗️ Apparatus Nessler Cylinders (2 pieces) Pipettes Beakers Glass rod 🔬 Procedure Test Solution Preparation Dissolve the given sample in water and add 5 mL of dilute HNO₃. Dilute to 50 mL with distilled water in a Nessler cylinder. Standard Solution Preparation Take 1 mL of 0.02% NaCl solution in another Nessler cylinder. Add 5 mL of dilute HNO₃ and make up to 50 mL with distilled water. Reaction To both cylinders, add 1 mL of 0.1N AgNO₃ solution. Mix well and allow to stand for 5 minutes. Observation View both cylinders against a black background. Compare the turbidity of the test solution with the standard solution. ⚛️ Chemical Reaction AgNO3+Cl−→AgCl↓(Whiteprecipitate)AgNO₃ + Cl⁻ → AgCl ↓ (White precipitate) AgNO3+Cl−→AgCl↓ (White precipitate) The white turbidity is due to the formation of silver chloride (AgCl). 📊 Observation Table SolutionObservation (Turbidity)Test Solution__________Standard Solution__________ ✅ Result If the turbidity of the test solution ≤ standard solution, the sample passes the limit test for chlorides. If the turbidity is more, the sample fails the test. ✍️ Viva Questions (for Students) What is the principle of the limit test of chlorides? Why is nitric acid added in this test? What is the role of AgNO₃? What is the appearance of the precipitate formed? 👉 Download full PDF of Limit Test of Chlorides Practical [here]
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