Strontium selenites

Chukhlantsev [56CHU] prepared strontium selenite by mixing 0.1 M solution of strontium chloride and sodium selenite solution in stoichiometric amounts. Chemical analysis confirmed the 1 1 ratio between Sr and Se(lV). No X-ray diffraction measurements were performed. The solubility of the specimen in dilute solution of nitric or hydrochloric acid was measured at 293 K. The data have been recalculated as described in Appendix A, [56CHU]. The result for  

Selivanova and Leshchinskaya [63SEL/LES] measured the enthalpy change of the reaction between equimolar quantities of SrCl2-6H20 and Na2Se03(aq, 1 1000) with formation of crystalline SrSeOs. Their data have been re-evaluated with new auxiliary data in Appendix A. The selected result is  

Reference [82WAG/EVA] reports - 1047.7 kJ-moP. The difference between the two values can be accounted for by the change in the data for strontium made in [92GRE/FUG]. The selected data further yield  

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Nitrogen (IV) oxide, 6 87 Nitrogen (V) oxide, 3 78 Nitrogen selenide, as explosive product in reduction of strontium selenite with ammonia, 3 21 N itropentamminechromium (III) nitrate, 5 133... 

Strontium nitrate, for preparation of strontium sulfate or strontium selenite, 3 17 Strontium selenide, 3 20 phosphors, 3 11, 22 Strontium selenite, for preparation of strontium selenide, 3 20 Strontium sulfate, for preparation of strontium sulfide, 3 19 Strontium sulfide, 3 20 phosphors, 3 11, 21, 23 Structure, of 1,3-diketones, 2 10 electronic, of rare earth elements, 2 30... 

Se03Sr Strontium selenite, 3 20 Se04H2 Selenic acid, 3 137 Se(S2CN(CH3)2)2 Selenium(II) di-methyldithiocarbamate, 4 93 Se(S2CN(C2H6)2)2 Selenium(II) di-ethyldithiocarbamate, 4 93 Se(S2COCH3)2 Selenium(II) meth-ylxanthate, 4 93... 

Solubility and thermodynamic properties of barium and strontium selenites, Zh. Fiz. Khim., 39, (1965), 2036-2038, in Russian, English translation in [65LES/AVE2]. Cited on pages 404, 407. 

Some of the procedures outlined below have been described previously. " They are designed for the preparation of phosphors that are to be used for quantitative studies of luminescence. Details are presented for the preparation of strontium nitrate, strontium chloride, strontium sulfate, and strontium selenite in a state of high purity for the reduction of the sulfate to the sulfide and the selenite to the selenide and for the conversion of the sulfide and the selenide into typical infrared-sensitive phosphors. 

The resulting strontium nitrate solution is now concentrated by evaporation until bumping commences. It is cooled and nitric acid distilled into the solution until precipitation ceases. The supernatant liquid is removed as completely as possible, emplo3dng the technique shown in Fig. 6. The crystalline mass is dissolved in the smallest possible quantity of doubly distilled water and the solution is filtered. The crystallization procedure is repeated twice, yielding as the final product a saturated solution of thrice recrystallized strontium nitrate. This solution is diluted to 500 ml. with doubly distilled water and is used for the precipitation of strontium sulfate or strontium selenite. 

Strontium Selenite. A solution of 77 g. of sublimed selenium(IV) oxide in 154 ml. of distilled water is added to 500 ml. of pure strontium nitrate solution prepared as previously described. The solution is heated to boiling and fresh ammonium hydroxide solution is added until no further precipitation of strontium selenite occurs. The precipitate is drained and washed six times with 300-mI. portions of hot distilled water. The nitrate content should be less than 5 parts per million as determined by the diphenylamine-sulfuric acid test. The strontium selenite is dried at 200° for several hours. The yield is about 125 g. 

SeOiSr Strontium selenite, 3 20 SeOiHs Selenic acid, 3 137 SeSr Strontium selenide, 8 11, 20, 22... 

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