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 + H₂S gas in presence of NH₄OH | White precipitate is formed | Group IV cation may be present |
| Confirmatory Tests | ||
| Sodium Hydroxide Test Add sodium hydroxide solution dropwise | White precipitate forms and dissolves in excess NaOH on heating | Zn²⁺ is confirmed |
| Potassium Ferrocyanide Test After neutralisation with NH₄OH, add potassium ferrocyanide solution | Bluish-white precipitate | Zn²⁺ is confirmed |
The given salt contains Zn²⁺ as the cation (basic radical) and I⁻ as the anion (acidic radical). The salt is Zinc Iodide (ZnI₂).