Cadmium Thiosulphate, CdS2O3.2H2O, is obtained by double decomposition between cadmium sulphate and barium or strontium thiosulphate. A colourless or yellowish oil separates when the solution, filtered free from insoluble sulphate, is treated with alcohol or alcohol and ether. After some time this oil solidifies into crystals.
The yellow-tinged crystals are monosymmetrical, retain their water in dry air, and decompose, gradually at low temperatures and quickly at high, according to the equation
4CdS2O3 = 3CdS+CdSO4+4SO2.
The double salts, as follows, have been prepared: Na2S2O3.3CdS2O3.9H2O, Na2S2O3.2CdS2O3.7H2O, and 3Na2S2O3.CdS2O3.9H2O; 3Na2S2O3.CdS2O3.16H2O, 3Na2S2O3.CdS2O3.3H2O; 5K2S2O3.3CdS2O3, 3K2S2O3.CdS2O3.2H2O; 3(NH4)2S2O3.CdS2O3.3H2O, 3(NH4)2S2O3.CdS2O3; 2BaS2O3.CdS2O3.8H2O, 3BaS2O3.CdS2O3.8H2O; 3SrS2O3.CdS2O3.10H2O. |