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 |
|---|---|---|
| Universal Indicator | Solution turns blue or purple | OH⁻ may be present |
| Confirmatory Test | ||
| Phenolphthalein Test Add phenolphthalein indicator to salt solution | Solution turns pink | OH⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Take 0.1 g of salt and add 1–2 mL of NaOH solution, then heat | A smell of ammonia is evolved | NH₄⁺ may be present |
| Bring a glass rod dipped in hydrochloric acid near the mouth of the test tube | Dense white fumes are observed | NH₄⁺ may be present |
| Confirmatory Test | ||
| Nessler's Reagent Test Pass the evolved gas through Nessler’s reagent | Brown colouration or a brown precipitate of basic mercury(II) amido-iodide is obtained | Presence of NH₄⁺ is confirmed |
The given salt contains NH₄⁺ as the cation (basic radical) and OH⁻ as the anion (acidic radical). The salt is Ammonium Hydroxide (NH₄OH).