STRONTIUM THIOSULFATE

Description

Strontium thiosulfate has the molecular formula of SrS₂O₃ and the molecular weight of 199.7502 g/mol. It can be prepared by the reaction of sodium thiosulfate upon the chloride:
SrCl2+Na2S2O3 ? SrS2O3+2NaCl
It is moderately soluble in water (12.5 g/100 ml at 15°C) so that the solution must be evaporated at a low temperature to crystallize the product (salt-out temperature ～15°F (-9.4°C). A pentahydrate, SrS2O3·5H2O, is the result.Its density is 2.17 g/cm3 and it loses four waters of hydration at 100°C and decomposes at 225°C. In air, it forms sulfur plus strontium sulfate but the decomposition in an inert atmosphere remains unknown.
It is insoluble in ethanol and acetone. Its solubility in water varies with temperature.

Chemical properties

Fine needles. Soluble in water; insoluble in alcohol.