Atomistry » Cobalt » Compounds » Ammonium Cobalt Alum
Atomistry »
  Cobalt »
    Compounds »
      Ammonium Cobalt Alum »

Ammonium Cobalt Alum, (NH4)2SO4.Co2(SO4)3

Ammonium Cobalt Alum, (NH4)2SO4.Co2(SO4)3.24H2O, was first prepared by Marshall, who, from a peculiar change in colour observed in the electrolysis of a solution of copper-cobalt potassium sulphate, was induced to electrolyse a solution of ammonium and cobalt sulphates, acidified with sulphuric acid in a divided cell.

The solution passes through a series of changes of colour, ultimately becoming greenish blue in consequence of the oxidation of the cobalt to the trivalent state. This suggested the formation of an alum, and by continuing the electrolysis for several days, and then concentrating the solution, blue octahedral crystals were obtained, a few crystals showing faces of dodecahedra and cubes. When thoroughly dry the crystals are not unstable, but their solution is quickly reduced, although the addition of dilute sulphuric acid increases its stability.

Last articles

Zn in 7VD8
Zn in 7V1R
Zn in 7V1Q
Zn in 7VPF
Zn in 7T85
Zn in 7T5F
Zn in 7NF9
Zn in 7M4M
Zn in 7M4O
Zn in 7M4N
© Copyright 2008-2020 by
Home   |    Site Map   |    Copyright   |    Contact us   |    Privacy