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 in a test tube and add conc. H₂SO₄ (or add MnO₂ if needed) and warm | Reddish brown fumes of bromine are evolved | Br⁻ may be present |
| Confirmatory Tests | ||
| Layer Test Take 1 mL of neutralized extract, add CCl₄/CHCl₃ (or other suitable organic solvent), then add chlorine water dropwise and shake vigorously | Orange-brown colouration appears in the organic layer | Br⁻ is confirmed |
| Silver Nitrate Test Acidify sodium carbonate extract with dilute HNO₃ (or use water extract) and add AgNO₃ | Pale yellow precipitate | Br⁻ 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 Br⁻ as the anion (acidic radical). The salt is Strontium Bromide (SrBr₂).