Notebook Theme

Experiment No. N

Analysis of Zinc Fluoride (Zn(F)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 the salt and treat with concentrated H₂SO₄Colourless gas evolves and it etches glassF⁻ may be present
Confirmatory Test
Calcium Chloride Test
Treat salt solution with calcium chloride solution
White gelatinous precipitate formsPresence of F⁻ is confirmed

Test of Cation

ExperimentObservationInference
Original solution + H₂S gas in presence of NH₄OHWhite precipitate is formedGroup IV cation may be present
Confirmatory Tests
Sodium Hydroxide Test
Add sodium hydroxide solution dropwise
White precipitate forms and dissolves in excess NaOH on heatingZn²⁺ is confirmed
Potassium Ferrocyanide Test
After neutralisation with NH₄OH, add potassium ferrocyanide solution
Bluish-white precipitateZn²⁺ is confirmed

Result

The given salt contains Zn²⁺ ions as cation and F⁻ ions as anion. The salt is Zn(F)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.