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Experiment No. N

Analysis of Magnesium Phosphate ((Mg)₃(PO₄)₂)

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
Confirmatory Test
Ammonium Molybdate Test
Acidify with conc. HNO₃ and add ammonium molybdate solution, boil
Canary yellow precipitate is formedPO₄³⁻ is confirmed

Test of Cation

ExperimentObservationInference
Confirmatory Test
If group-V is absent, add disodium hydrogen phosphate solution and scratch the inner walls with a glass rodA white crystalline precipitate of magnesium ammonium phosphate is formedMg²⁺ is confirmed

Result

The given salt contains Mg²⁺ ions as cation and PO₄³⁻ ions as anion. The salt is (Mg)₃(PO₄)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.