Nomenclature
CAS number: 10049-05-5
Cl
2Cr; mol wt 122.90.
Cl 57.69%, Cr 42.31%.
CrCl
2.
Description and 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).Derivative
Tetrahydrate.
Nomenclature
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 O
2 absorbent; in analysis.