metal

• [Cu(H2O)6] 2+


  pale blue solution
• Cu(OH)2 (s)


  pale blue precipitate
• [Cu(NH3)4(H2O)2] 2+


  dark blue solution
• CuCl42-

  yellow solution
• disproportionation of copper: Cu+ --> Cu + Cu2+

  
  

  CuI --> Cu + CuSO4
• Cu+ in CuI: white precipitate

  
  

  in a brown I2 solution
• Cu2+ in CuSO4


  blue solution
• Cu metal (s)


  brown solid
• CoCl4 2-


  blue solution
• [Cr(H2O)6] 3+


  pale purple solution or green if impurities
• Cr(OH)3 (s)


  dark green precipitate
• [Cr(NH3)6] 3+


  purple solution
• [Cr(OH)6] 3-


  dark green solution
• Cr2O7 2-


  orange solution
• CrO4 2-


  yellow solution
• [Mn(H2O)6]2+


  pale pink solution
• Mn(OH)2 (s)


  pale brown precipitate
• [Fe(H2O)6]2+


  pale green solution
• Fe(OH)2 (s)


  dark green precipitate
• [Fe(H2O)6]3+


  yellow solution
• Fe(OH)3 (s)


  orange-brown precipitate
• Fe2+ --> Fe3+


  purple --> pink

  Fe2+
• in MnO4-


  purple solution

  Fe3+
• in Mn2+


  pale pink solution
• Fe3+ --> Fe2+


  orange-brown (Fe3+)

  
  

  brown (I2)

  I2
• with Fe2+


  brown solution (I2)

  Fe3+
• in I-


  orange-brown solution