Ethylenediamine Complexes of Nickel

Hazards

  • Nickel sulfate is considered a cancer suspect agent.
  • Ethylenediamine in ethanol is flammable and corrosive.

Chemicals and Solutions

  • 400 mL 0.lM nickel (II) sulfate
  • 10 mL 25% ethylenediamine solution in ethanol

Materials

  • four tall cylinders
  • eyedropper
  • glass stirring rods

Or

  • pre-prepared display of the ethylenediamine complexes of nickel

Procedure

  1. Place 100 mL of the nickel (II) sulfate solution into each of the cylinders.
  2. To one cylinder add a few drops (about 0.5 mLs) of the ethylenediamine solution to get the green-blue color of \( \ce{ Ni(H2O)4en2+ } \)
  3. To the next cylinder add one or two mL of the ethylenediamine solution to get the blue color of \( \ce{Ni(H2O)2(en)22+ } \)
  4. To the third cylinder add about 4 mL of the ethylenediamine solution to get the violet color of \( \ce{Ni(en)32+ } \)