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 |
|---|---|---|
| Confirmatory Test | ||
| Ammonium Molybdate Test Acidify with conc. HNO₃ and add ammonium molybdate solution, boil | Canary yellow precipitate is formed | PO₄³⁻ 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 PO₄³⁻ as the anion (acidic radical). The salt is Magnesium Phosphate (Mg₃(PO₄)₂).