To determine the presence of anion and cation in the given salt
| Experiment | Observation | Inference |
|---|---|---|
| Universal Indicator | Solution turns blue or purple | OH⁻ may be present |
| Confirmatory Test | ||
| Phenolphthalein Test Add phenolphthalein indicator to salt solution | Solution turns pink | OH⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Confirmatory Test | ||
| If group-V is absent, add disodium hydrogen phosphate solution and scratch the inner walls with a glass rod | A white crystalline precipitate of magnesium ammonium phosphate is formed | Mg²⁺ is confirmed |
The given salt contains Mg²⁺ ions as cation and OH⁻ ions as anion. The salt is Mg(OH)₂.