Notebook Theme

Experiment No. N

Analysis of Nickel(II) Hydroxide (Ni(OH)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
Universal IndicatorSolution turns blue or purpleOH⁻ may be present
Confirmatory Test
Phenolphthalein Test
Add phenolphthalein indicator to salt solution
Solution turns pinkOH⁻ is confirmed

Test of Cation

ExperimentObservationInference
Original solution + H₂S gas in presence of NH₄OHBlack precipitate is formedGroup IV cation may be present
Dissolve black precipitate in aqua regiaNickel chloride solution is obtainedNi²⁺ may be present
Confirmatory Test
Dimethylglyoxime Test
Make the solution alkaline with NH₄OH and add dimethylglyoxime
Brilliant red precipitatePresence of Ni²⁺ is confirmed

Result

The given salt contains Ni²⁺ ions as cation and OH⁻ ions as anion. The salt is Ni(OH)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.