Notebook Theme

Experiment No. N

Analysis of Barium Oxalate (BaC₂O₄)

Aim

To determine the presence of anion and cation in the given salt

Preliminary Test

  • Odor: Odorless
  • Texture: Crystalline
  • Color: White
  • Solubility: Slightly soluble in water

Test of Anion

ExperimentObservationInference
Take 0.1 g salt and add conc. H₂SO₄Colourless gases are evolved. On testing further, CO₂ and CO are evolvedC₂O₄²⁻ may be present
Confirmatory Tests
Calcium Chloride Test
Acidify extract with acetic acid and add calcium chloride
White precipitate of calcium oxalate is obtainedC₂O₄²⁻ is confirmed
KMnO₄ Test
Filter and add dilute H₂SO₄ to the precipitate, then dilute KMnO₄ and warm
KMnO₄ pink colour is dischargedC₂O₄²⁻ is confirmed

Test of Cation

ExperimentObservationInference
Original solution + Dilute HClNo reactionGroup I cation is absent
Original solution + Dilute HCl + H₂S gas (with NH₄Cl)No reactionGroup II cation is absent
Original solution + Dilute HCl + NH₄Cl solid + NH₄OHNo reactionGroup III cation is absent
Original solution + NH₄Cl + NH₄OH + (NH₄)₂CO₃White ppt is formedGroup V cation may be present
Confirmatory Test
Potassium Chromate Test
Dissolve the white precipitate in dilute acetic acid and add potassium chromate
Yellow precipitateBa²⁺ is confirmed

Result

The given salt contains Ba²⁺ ions as cation and C₂O₄²⁻ ions as anion. The salt is BaC₂O₄.

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.