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 |
|---|---|---|
| Add conc. H₂SO₄ to the solution and boil with a few copper turnings/chips | On heating, brown fumes (NO₂) are evolved in excess and the solution becomes blue | NO₃⁻ may be present |
| Confirmatory Test | ||
| Brown Ring Test Take 1 mL of salt solution, add 2 mL conc. H₂SO₄, cool, then add freshly prepared ferrous sulphate solution along the sides | Brown ring is formed at the junction of the two solutions | NO₃⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + Dilute HCl | No reaction | Group I cation is absent |
| Original solution + Dilute HCl + H₂S gas (with NH₄Cl) | No reaction | Group II cation is absent |
| Original solution + Dilute HCl + NH₄Cl solid + NH₄OH | No reaction | Group III cation is absent |
| Original solution + NH₄Cl + NH₄OH + (NH₄)₂CO₃ | White precipitate is formed | Group V cation may be present |
| Confirmatory Tests | ||
| Flame Test Moisten the salt with conc. HCl and introduce it into a non-luminous flame | Crimson-red flame | Sr²⁺ is confirmed |
| Ammonium Sulphate Test Dissolve white precipitate in dilute acetic acid and add ammonium sulphate solution | White precipitate of strontium sulphate | Sr²⁺ is confirmed |
The given salt contains Sr²⁺ as the cation (basic radical) and NO₃⁻ as the anion (acidic radical). The salt is Strontium Nitrate (Sr(NO₃)₂).