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 + H₂S gas in presence of NH₄OH | Black precipitate is formed | Group IV cation may be present |
| Dissolve black precipitate in aqua regia | Nickel chloride solution is obtained | Ni²⁺ may be present |
| Confirmatory Test | ||
| Dimethylglyoxime Test Make the solution alkaline with NH₄OH and add dimethylglyoxime | Brilliant red precipitate | Presence of Ni²⁺ is confirmed |
The given salt contains Ni²⁺ as the cation (basic radical) and NO₃⁻ as the anion (acidic radical). The salt is Nickel(II) Nitrate (Ni(NO₃)₂).