Hydrogen selenite

A less well-documented effect is that of the phase-transition temperature of certain crystals which are very sensitive to deuteration. Some crystals of ferroelectric and antiferroelectric materials, and in particular dihydrogen phosphates and hydrogen selenites, which are extensively hydrogen bonded, display this effect (Blinc and Zeks, 1974). For some crystals, such as caesium... 

Mercuric selenite., IIgSe03, prepared by the action of sodium hydrogen selenite on mercuric oxide, forms double salts of the types Na2Hg(Se03)2 and HgCl. SeOgNa.2H20.12... 

Berzelius mentions a salt which was either sodium hydrogen selenite, NaHSeOa, or pyroselenite, Na2Se2Os. 

The solubility of Na2Sc205(cr) has been studied by Janitzki [32JAN], The compound is stable only above (366.2 0.5) K in the aqueous environment. Below this temperature it transforms to hydrogen selenites. The solubility at the transition temperature is about 11.0 mol kg... 

Silver selenite was prepared by addition of a selenious acid solution to a solution of silver nitrate. The product was recrystallised three times from nitric acid ( ). Sodium hydrogen selenite solution was prepared by neutralisation of recrystallised selenious acid by carbonate-free sodium hydroxide. The silver-silver selenite electrodes were obtained by first electroplating silver onto a platinum foil and then converting some of the silver to silver selenite by further anodic electrolysis. The procedure was apparently the same as used for the preparation of silver-silver chloride electrodes. The experiments were carried out in the dark or in subdued daylight. 

Crystalline lithium hydrogen selenite was prepared and checked by X-ray and chemical analysis. The enthalpy of the reaction between a solution of the salt and Pb(N03)2(cr) was determined as well as the heat of dissolution of LiHSeOs. The experimental findings are furnished in Table A-65, in which the enthalpy change of the reaction LiHSeOsCcr) + Pb —> PbSeOsCcr) + Li + H is calculated. 

Sodium hydrogen selenite was prepared and the specimen checked by X-ray and chemical analysis. The enthalpy of reaction between solid NaHSe03 and a solution of lead nitrate with formation of crystalline lead selenite was measured in an electrically calibrated calorimeter. The result is used in Table A-67 to calculate the enthalpy of the reaction NaHSe03(cr) + Pb -> PbSe03(cr) + + Na. ... 

ROS/SEL] Roshchina, Z. V., Selivanova, N. M., Heat of formation of lithium hydrogen selenite LiHSeOs, 7>. Inst.-Mask. Khim.-Tekhnol. Inst, im. D. /. Mendeleeva, 58, (1968), 7-10, in Russian. Cited on pages 414,502. 

HYDROGEN SELENITE (7783-00-8) SeO(OH)j HiSeO, Reacts with air, forming selenium oxide and water. Reacts with oxidizers, forming selenic acid and vnth reducing agents, forming selenium. Aqueous solution incompatible with sulfuric acid, caustics, ammonia, aliphatic amines, alkanolamines, amides, organic anhydrides, isocyanates, vinyl acetate, alkylene oxides, epichlorohydrin. 

Selenious acid (hydrogen selenite) CASRN 7783-00-8 White powder encountered as 2% solution in gun bluing Ingestion of as little as 15 mL of a 2% solution was reported fatal in a child. 

Lithium hydrogen selenite has been prepared in 95% yield by neutralization of a selenious acid solution with LiOH to pH 4—4.5. 

Hydrogen selenite (selenous acid) (Other values on Vol.4, p.91)... 

---