Notebook Theme

Experiment No. N

Analysis of Potassium Fluoride (K⁺F⁻)

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
Salt + Conc H₂SO₄Colorless gas evolves that etches glassF⁻ may be present
Confirmatory Test
Calcium Chloride Test
Salt Solution + CaCl₂ solution
White gelatinous ppt formsPresence of F⁻ anion is confirmed

Test of Cation

ExperimentObservationInference
Flame testLilac flamePresence of K⁺ is indicated
Confirmatory Test
Sodium Cobaltinitrite Test
Salt solution + Sodium Cobaltinitrite reagent
Yellow precipitatePresence of K⁺ is confirmed

Result

The given salt contains K⁺ ions as cation and F⁻ ions as anion. The salt is K⁺F⁻.

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.