To determine the presence of anion and cation in the given salt
| Experiment | Observation | Inference |
|---|---|---|
| Add conc. H₂SO₄ to the solution and boil with a few copper turnings/chips | On heating, brown fumes (NO₂) are evolved in excess and the solution becomes blue | NO₃⁻ may be present |
| Confirmatory Test | ||
| Brown Ring Test Take 1 mL of salt solution, add 2 mL conc. H₂SO₄, cool, then add freshly prepared ferrous sulphate solution along the sides | Brown ring is formed at the junction of the two solutions | NO₃⁻ 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⁺ ions as cation and NO₃⁻ ions as anion. The salt is NH₄NO₃.