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 the salt and treat with concentrated H₂SO₄ | Colourless gas evolves and it etches glass | F⁻ may be present |
| Confirmatory Test | ||
| Calcium Chloride Test Treat salt solution with calcium chloride solution | White gelatinous precipitate forms | Presence of F⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + H₂S gas in presence of NH₄OH | White precipitate is formed | Group IV cation may be present |
| Confirmatory Tests | ||
| Sodium Hydroxide Test Add sodium hydroxide solution dropwise | White precipitate forms and dissolves in excess NaOH on heating | Zn²⁺ is confirmed |
| Potassium Ferrocyanide Test After neutralisation with NH₄OH, add potassium ferrocyanide solution | Bluish-white precipitate | Zn²⁺ is confirmed |
The given salt contains Zn²⁺ as the cation (basic radical) and F⁻ as the anion (acidic radical). The salt is Zinc Fluoride (ZnF₂).