Cesium cobalt alum

CESIUM COBALT(III) SULFATE 12-HYDRATE (Cesium Cobalt(fll) Alum)... 

Cesium is determined as the tetraphenylborate, total cobalt as the anthranilate, sulfate as barium sulfate, and cobalt(III) by addition of the alum to excess of potassium iodide solution followed by titration with thiosulfate- Anal. Calcd. -for CsCo(S04)2-12H20 Cs, 22.2 Co, 9.82 S04, 32.0. Found Cs, 22.2 Co, 9.83 S04, 32.3 Co(III), 9.80. 

The only known solid compounds containing the ion Co(H20)6 are the sulfate Co2(S04)3 18H20 and its alums. Although the first synthesizer of the sulfate reported he was able to store it in a stoppered tube for months without visible decomposition, later authors stated that this compound and the ammonium alum decompose at laboratory temperature within a few hours. By an improved drying procedure, the cesium alum is readily obtained in a form in which even the magnetic susceptibility (a very sensitive criterion for the presence of dipositive cobalt) shows that only very slow decomposition occurs. Use of this... 

---