Title: Selenious Acid
CAS Registry Number: 7783-00-8
Additional Names: Monohydrated selenium dioxide; selenous acid
Molecular Formula: H2O3Se
Molecular Weight: 128.97
Percent Composition: H 1.56%, O 37.22%, Se 61.22%
Line Formula: H2SeO3
Literature References: Prepd by dissolving selenium dioxide in hot water and cooling: Berzelius, Acad. Handl. Stockholm 39, 13 (1818).
Properties: Deliquescent hexagonal prisms; d415 3.004. Vapor press. (mm Hg): 2 at 15°; 4.5 at 35°; 7 at 40.3°. K1 = 0.0024; K2 = 4.8 ´ 10-9. Gives off water upon heating and selenium oxide sublimes. Oxidized to selenic acid by strong oxidizing agents such as ozone, hydrogen dioxide, chlorine. Reduced to selenium by most reducing agents including hydriodic acid, sulfurous acid, sodium hyposulfite, hydroxylamine salts, hydrazine salts, hypophosphorous acid, phosphorous acid. 90 parts dissolve in 100 parts water at 0°, 400 parts at 90°; very sol in alcohol; insol in ammonia.
Density: d415 3.004
Use: As a reagent for alkaloids; as oxidizing agent. |