Qualitative analysis
How to do salt analysis · Viva · Quiz
To analyse the given inorganic salt for one acidic and one basic radical.
| Experiment | Observation | Inference |
|---|---|---|
| Take 0.1 g of salt in a test tube and add conc. H₂SO₄ | Deep violet vapour with a pungent odour is evolved | I⁻ may be present |
| Confirmatory Tests | ||
| Layer Test Take test solution or extract, add CHCl₃/CCl₄ and chlorine water dropwise, then shake vigorously | Violet colouration appears in the organic layer | I⁻ is confirmed |
| Silver Nitrate Test Acidify sodium carbonate extract with dilute HNO₃ and add AgNO₃ | Yellow precipitate is obtained, insoluble in excess NH₄OH | I⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + Dilute HCl | White precipitate | Pb²⁺ may be present |
| Confirmatory Tests | ||
| Potassium Iodide Test Dissolve one part of the hot precipitate in hot water and add potassium iodide solution | Yellow precipitate is formed | Presence of Pb²⁺ is confirmed |
| Potassium Chromate Test To the acidified solution obtained above, add potassium chromate solution | Yellow precipitate is formed | Presence of Pb²⁺ is confirmed |
| Lead Sulphate Test Dissolve lead sulphide precipitate in dilute HNO₃, then add a few drops of dilute H₂SO₄ and alcohol | White precipitate of lead sulphate is formed | Presence of Pb²⁺ is confirmed |
The given salt contains Pb²⁺ as the cation (basic radical) and I⁻ as the anion (acidic radical). The salt is Lead(II) Iodide (PbI₂).