Strontium Periodides

By exposure to light of the mother liquor of the double strontium lead iodide, golden-brown crystals of strontium tri-iodide, SrI₃.15H₂O, are obtained.

Solid periodides can be obtained by fusing together iodine and strontium iodide in the proper proportions on the water-bath.

The dissociation constant of strontium tetra-iodide in aqueous solutions has been determined by distribution methods. For a 0.1246 molar solution of strontium iodide the dissociation constant "k" is about 0.00097 at 25° C., when all concentrations are expressed in gram- molecules per litre. The existence of periodides in nitrobenzene solution up to the ennea-iodide, SrI₁₈, has also been demonstrated.