To determine the presence of anion and cation in the given salt
| 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 |
|---|---|---|
| Salt solution + NaOH solution | Dirty green precipitate | Fe²⁺ may be present |
| Confirmatory Test | ||
| Potassium Ferricyanide Test Add potassium ferricyanide solution | Dark blue precipitate (Turnbull's blue) | Presence of Fe²⁺ is confirmed |
The given salt contains Fe²⁺ ions as cation and I⁻ ions as anion. The salt is Fe(I)₂.