Title: Hydrogen Selenide
CAS Registry Number: 7783-07-5
Additional Names: Selenium hydride
Molecular Formula: H2Se
Molecular Weight: 80.98
Percent Composition: H 2.49%, Se 97.51%
Literature References: Prepd by heating selenium and hydrogen in a sealed tube at 440°: Hautefeuille, Bull. Soc. Chim. [2] 7, 198 (1867); by passing a mixture of hydrogen and selenium vapor over pumice stone at 440°: Corenwinder, Ann. Chim. Phys. [3] 34, 77 (1852); by warming potassium or ferrous selenide with hydrochloric acid: Berzelius, Acad. Handl. Stockholm 39, 13 (1818); by the action of water on aluminum selenide: Fonzes-Diacon, Traité de Chimie Minérale, Paris 1, 469 (1904); Waitkins, Shutt, Inorg. Synth. 2, 183 (1946). Review of chemistry and toxicity: Medical and Biologic Effects of Environmental Pollutants: Selenium (Nat. Acad. Sci., Washington D.C., 1976) 203 p.
Properties: Gas. Disagreeable odor. Highly toxic and reactive gas that decomposes rapidly in presence of oxygen to form elemental Se and H2O. d4-42 2.12. bp -41.3°. Liquefies at 0° under a pressure of 6.6 atm; at 18°, 8.6 atm; at 52°, 21.5 atm; at 100°, 47.1 atm; at the crit temp 137°, 91.0 atm. mp -65.73°. v.p. at -30°, 1.75 atm; v.p. at 0.2°, 4.5 atm; v.p. at 30.8°, 12 atm. K1 at 25° = 1.30´10-4; K2 at 25° = 1´10-11. Soly in water (ml/100 ml): 377 (4°); 270 (22.5°). Sol in carbonyl chloride and carbon disulfide. Unites directly with most metals to form metal selenides.
Melting point: mp -65.73°
Boiling point: bp -41.3°
Density: d4-42 2.12
CAUTION: Potential symptoms of overexposure are irritation of eyes, nose and throat; nausea, vomiting and diarrhea; metallic taste, garlic breath; dizziness, lassitude and fatigue; direct contact with liquid may cause frostbite. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 168. |