Notebook Theme

Experiment No. N

Analysis of Barium Iodide (Ba(I)₂)

Aim

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

Preliminary Test

  • Odor: Odorless
  • Texture: Crystalline
  • Color: White
  • Solubility: Soluble in water

Test of Anion

ExperimentObservationInference
Take 0.1 g of salt in a test tube and add conc. H₂SO₄Deep violet vapour with a pungent odour is evolvedI⁻ may be present
Confirmatory Tests
Layer Test
Take test solution or extract, add CHCl₃/CCl₄ and chlorine water dropwise, then shake vigorously
Violet colouration appears in the organic layerI⁻ is confirmed
Silver Nitrate Test
Acidify sodium carbonate extract with dilute HNO₃ and add AgNO₃
Yellow precipitate is obtained, insoluble in excess NH₄OHI⁻ 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 I⁻ ions as anion. The salt is Ba(I)₂.

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.