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Analysis of Ammonium Acetate (NH₄CH₃COO)

Qualitative analysis

Aim

To analyse the given inorganic salt for one acidic and one basic radical.

Preliminary Test

  • Colour: White
  • Odour: Ammoniacal
  • State: Crystalline solid
  • Solubility: Soluble in water

Test of Anion (CH₃COO⁻)

ExperimentObservationInference
Take 0.1 g salt + dilute H₂SO₄Colourless vapours with vinegar-like smell evolveCH₃COO⁻ 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 developedCH₃COO⁻ 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 formsCH₃COO⁻ is confirmed

Test of Cation (NH₄⁺)

ExperimentObservationInference
Take 0.1 g of salt and add 1–2 mL of NaOH solution, then heatA smell of ammonia is evolvedNH₄⁺ may be present
Bring a glass rod dipped in hydrochloric acid near the mouth of the test tubeDense white fumes are observedNH₄⁺ may be present
Confirmatory Test
Nessler's Reagent Test
Pass the evolved gas through Nessler’s reagent
Brown colouration or a brown precipitate of basic mercury(II) amido-iodide is obtainedPresence of NH₄⁺ is confirmed

Result

The given salt contains NH₄⁺ as the cation (basic radical) and CH₃COO⁻ as the anion (acidic radical). The salt is Ammonium Acetate (NH₄CH₃COO).

Precautions

  1. Handle the chemicals with care.
  2. Don't use excess of chemicals.
  3. Keep the mouth of the test tube away from the face.