Strontium Nitrite, Sr(NO₂)₂

Strontium Nitrite, Sr(NO₂)₂, is prepared similarly to the calcium salt by the action of silver nitrite on strontium chloride. It has a yellow colour more pronounced than that of calcium nitrite, and crystallises at ordinary temperatures as the monohydrate of density 2.408. By evaporation at 70°-80° C. the anhydrous salt is obtained. It melts, and at the same time decomposes, at about 240° C.

The molecular volumes of the nitrides have been studied by Ray. Oswald has determined the solubility in water and obtained the following values: -

Temperature, 0 C	0	20	40	60	80	100
Parts Sr(NO2)2.H2O per 100 parts water.	58.9	75.5	94	116	145	182

The saturated solution boils at 112.5° C. under a pressure of 763 mm., and there is slow but decided hydrolysis. The cryohydric temperature is -6.8° C., and the composition of the solution 32.8 per cent, of nitrite.

A double salt with caesium, CsSr(NO₂)₃.H₂O, and a triple salt with caesium and silver, Cs₃AgSr(NO₂)₆.2H₂O, are known, and also a double strontium mercury salt, 3Hg(NO₂)₂.2Sr(NO₂)₂.5H₂O.