transition metal complexes

• generally

  • copper II - blue
  • iron II - green
  • iron III - brown
  • aluminium III - colourless or white precipitate
• hexaaqua copper (II)

  clear blue solution

  [Cu(H2O)6] ^2+
• hexaaqua iron (II)

  green solution

  [Fe(H2O)6] ^2+
• hexaaqua iron (III)

  yellow solution

  [Fe(H2O)6] ^3+
• hexaaqua aluminium (III)

  colourless solution

  [Al(H2O)6] ^3+
• CuCO3 forms a green blue precipitate
• [CuCl4]^2- forms a yellow solution
• [Cu(H2O)4(OH)2] forms a pale blue precipitate
• [Cu(NH3)4(H2O)2]^2+ forms a deep blue solution
• [Cu(H2O)6]^2+ forms a clear blue solution
• [Fe(H2O)6]^2+ forms a green solution
• FeCO3 forms a green precipitate
• [Fe(H2O)4(OH)2] forms a dirty green precipitate
• [Fe(H2O)6]^3+ forms a yellow solution
• [Fe(H2O)3(OH)3] forms a brown precipitate
• [Al(H2O)6]^3+ forms a colourless solution
• [Al(H2O)3(OH)3] forms a white precipitate
• [Al(OH)4]^- forms a colourless solution
• iron III is yellow like a bee