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 salt and add conc. H₂SO₄ | Colourless gases are evolved. On testing further, CO₂ and CO are evolved | C₂O₄²⁻ may be present |
| Confirmatory Tests | ||
| Calcium Chloride Test Acidify extract with acetic acid and add calcium chloride | White precipitate of calcium oxalate is obtained | C₂O₄²⁻ is confirmed |
| KMnO₄ Test Filter and add dilute H₂SO₄ to the precipitate, then dilute KMnO₄ and warm | KMnO₄ pink colour is discharged | C₂O₄²⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Confirmatory Tests | ||
| If Group V is absent, add disodium hydrogen phosphate solution and scratch the inner walls with a glass rod | A white crystalline precipitate of magnesium ammonium phosphate is formed | Mg²⁺ may be present |
| Magneson Test To the alkaline solution add a drop of Magneson I reagent (p-nitrobenzeneazoresorcinol) | A blue precipitate / blue lake is formed | Mg²⁺ is confirmed |
The given salt contains Mg²⁺ as the cation (basic radical) and C₂O₄²⁻ as the anion (acidic radical). The salt is Magnesium Oxalate (MgC₂O₄).