To determine the presence of anion and cation in the given salt
| Experiment | Observation | Inference |
|---|---|---|
| Confirmatory Tests | ||
| If no earlier anion test is positive, acidify the extract with dilute HCl and add BaCl₂ solution | White precipitate of barium sulphate, insoluble in conc. HCl or conc. HNO₃ is obtained | SO₄²⁻ may be present |
| Lead Acetate Test Acidify the solution with acetic acid and add lead acetate solution | White precipitate appears | Presence of SO₄²⁻ 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 SO₄²⁻ ions as anion. The salt is (NH₄)₂SO₄.