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, add 1–2 mL of dilute H₂SO₄ | Colourless odourless gas is evolved with brisk effervescence; lime water turns milky | CO₃²⁻ may be present |
| Confirmatory Test | ||
| Lime Water Test Pass the gas through lime water | Lime water turns milky; milkiness disappears on passing excess gas (soluble calcium bicarbonate) | CO₃²⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + H₂S gas in presence of dil. HCl | Black precipitate of Group-II A is formed | Group-II cation may be present |
| Confirmatory Tests | ||
| Ammonium Hydroxide Test To the original solution (or the filtrate after dissolving the black ppt in dilute HNO₃) add NH₄OH dropwise, then in excess | Pale blue precipitate of Cu(OH)₂ dissolves in excess NH₄OH giving a deep blue tetraamminecopper(II) solution | Cu²⁺ is confirmed |
| Potassium Ferrocyanide Test Acidify the solution with acetic acid and add potassium ferrocyanide | Chocolate-brown precipitate of copper ferrocyanide | Presence of Cu²⁺ is confirmed |
The given salt contains Cu²⁺ as the cation (basic radical) and CO₃²⁻ as the anion (acidic radical). The salt is Copper(II) Carbonate (CuCO₃).