Sodium selenosulfate

In a cychc method selenium is dissolved in hot sodium sulfite solution to form sodium selenosulfate [25468-09-1]. 

Other inorganic selenium compounds include sodium selenocyanate [4768-87-0], NaSeCN, which is prepared by melting together selenium and sodium cyanide selenocyanogen [27151 -67-3] (SeCN)2 sodium selenosulfate [25468-09-1], Na2SeS02, which is prepared by dissolving selenium in aqueous sodium sulfite (acidification decomposes this compound) and selenate alums, eg, Al2(Se0 2 I SeO [13530-59-1]. 

While most mechanistic investigations have been carried out on CdS, other semiconductors, in particular CdSe, have also been studied with regard to the deposition mechanism. Kainthla et al., in their study of the formation of CdSe films from ammoniacal solutions containing sodium selenosulfate, noted that when a visible precipitate of Cd(OH)2 was present in their solutions (obtained by adding... 

Fig. 22. HREM image of CdSe deposited from a solution containing sodium selenosulfate and cadmium sulfate as precursors complexing agent NTA with R ([NTA]/[Cd]) = 2.2 (R > Rc).

Hydrolysis of sodium selenosulfate takes place in solution, which releases selenide ions ... 

When a portion of a solid sample or its solution is treated with excess ammonium hydroxide and ammonium carbonate and the resulting suspension filtered if necessary, the clear solution may contain the ammoniates of palladium, silver, cadmium, copper, nickel, and also thallium ions. The addition of sodium selenosulfate to this solution yields a brown precipitate if Pd, Ag or T1 ions are present, while the other ions remain unaffected. On warming, the brown color changes to black. The initial selenosulfates are possibly transformed into selenides ... 

B. Insoluble Calcium Salts (1) Test for calcium sulfate with sodium selenosulfate ... 

Because of the marked difl[erence in the water solubility of CaS04 and CaSOs (0.2016 g/100 ml and 0.0045 g/100 ml), the latter is formed by treatment of the sulfate with alkali sulfite. However, this conversion is not directly observable, but if a solution of sodium selenosulfate is used as a SOs donor, the slow deposition of red elemental selenium indicates the formation of calcium sulfite ... 

If several drops of the aqueous solution of the sample are taken to dryness and then ignited, the residues will contain calcium oxide or calcium sulfate, respectively. If spotted with sodium selenosulfate solution, red selenium will be deposited. Salts of barium, strontium, and magnesium do not show this behavior. 

As outlined in the previous chapter, calcium sulfate can be detected by its reaction with sodium rhodizonate (see page 160) or sodium selenosulfate (see page 164). These tests can be applied in mineral investigations to identify gypsum and anhydrite. 

This procedure may be conducted within the technique of spot test analysis. Quantities of the sample less than 0.5 mg are adequate. See page 165 regarding the preparation of the sodium selenosulfate solution. 

Precipitation route Cadmium acetate, Na2SeS03, sodium selenosulfate CNa2SeS03), CdCb Ammonia solution to control pH 2-mercaptoethanol - [185] [186]... 

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