| Title:  Chromous Chloride CAS Registry Number:  10049-05-5 Molecular Formula:  Cl2Cr Molecular Weight:  122.90 Percent Composition:  Cl 57.69%, Cr 42.31% Line Formula:  CrCl2 Literature References:  Prepn:  Burg, Inorg. Synth. 3, 150 (1950); Hein, Herzog, in Handbook of Preparative Inorganic Chemistry Vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed. 1965) pp 1336-1338.  Prepn of tetrahydrate:  Balthis, Jr., Bailar, Jr., Inorg. Synth. 1, 125 (1939); Holah, Fackler, ibid. 10, 26 (1967).  Toxicity study:  H. F. Smyth et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969). Properties:  Lustrous needles or fused, fibrous mass.  mp 824°; d414 2.751.  Very hygroscopic; stable in dry air but oxidizes rapidly if moist.  Powerful reducing agent.  Soluble in water giving a blue soln.  Keep well closed.  LD50 orally in rats:  1.87 g/kg (Smyth). Melting point:  mp 824° Density:  d414 2.751 Toxicity data:  LD50 orally in rats:  1.87 g/kg (Smyth)   Derivative Type:  Tetrahydrate  Additional Names:  Tetraaquochromium dichloride Properties:  Bright blue, hygroscopic crystals.  Above 38° changes to isomeric green modification.  Loses 1H2O, forming trihydrate, at 51°.  Absorbs O2 even when dry, forming a greenish-black oxychloride.  Sol in water.  Almost insol in concd HCl.  On standing in soln it is oxidized by the water with liberation of H2.  Keep well closed.   Use:  In chromizing; in prepn of Cr metal; in catalysts for organic reactions; as O2 absorbent; in analysis.  |