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 0.1 g salt + dilute H₂SO₄ | Colourless vapours with vinegar-like smell evolve | CH₃COO⁻ may be present |
| Confirmatory Tests | ||
| Ester Test Take 0.1 g salt in a test tube with ethanol and a little conc. H₂SO₄, then heat | Fruity odour of ethyl acetate is developed | CH₃COO⁻ is confirmed |
| Ferric Chloride Test Add neutral ferric chloride solution to the salt solution | Deep red colour appears; on heating it disappears and a brown-red precipitate forms | CH₃COO⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Original solution + Dil. HCl + NH₄Cl solid + NH₄OH | White gelatinous precipitate | Al³⁺ may be present |
| Confirmatory Tests | ||
| Dissolve white precipitate in dilute HCl and divide into two parts | To the first part, add sodium hydroxide and warm. A white gelatinous precipitate dissolves in excess sodium hydroxide solution | Aluminium is confirmed |
| Blue Lake Test To the second part, add few drops of blue litmus solution and then NH₄OH dropwise along the sides of the test tube | A blue floating mass appears in colourless solution | Presence of Al³⁺ is confirmed |
The given salt contains Al³⁺ as the cation (basic radical) and CH₃COO⁻ as the anion (acidic radical). The salt is Aluminium Acetate (Al(CH₃COO)₃).