To determine the presence of anion and cation in the given salt
| 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 | 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⁺ ions as cation and F⁻ ions as anion. The salt is Ni(F)₂.