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 |
|---|---|---|
| Warm the salt with dilute H₂SO₄ | Colourless gas with smell of rotten eggs is evolved | S²⁻ may be present |
| Confirmatory Tests | ||
| Lead Acetate Test Pass gas through filter paper dipped in lead acetate solution | Paper turns black | S²⁻ is confirmed |
| Sodium Nitroprusside Test Make solution alkaline with NH₄OH (or sodium carbonate extract) and add sodium nitroprusside solution | Purple/violet colouration is produced | S²⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + H₂S gas in presence of NH₄OH | Black or flesh-coloured precipitate is formed | Group IV cation may be present |
| Confirmatory Test | ||
| Sodium Hydroxide Test Dissolve the precipitate in dilute HCl by boiling and add NaOH in excess | White precipitate forms first, then turns brown on standing | Presence of Mn²⁺ is confirmed |
The given salt contains Mn²⁺ as the cation (basic radical) and S²⁻ as the anion (acidic radical). The salt is Manganese(II) Sulphide (MnS).