Title: Cuprous Oxide
CAS Registry Number: 1317-39-1
Synonyms: Red copper oxide; C.I. 77402; yellow cuprocide
Trademarks: Cacobre (Syngenta); Cooper-Sandoz (Syngenta)
Molecular Formula: Cu2O
Molecular Weight: 143.09
Percent Composition: Cu 88.82%, O 11.18%
Literature References: Occurs in nature as the mineral
cuprite (red to reddish-brown octahedral or cubic crystals). Prepd commercially by furnace reduction of mixtures of copper oxides with Cu: Drapeau, Johnson,
US 2758014;
US 2891842 (1956, 1959 both to Glidden); by decompn of copper ammonium carbonate: Rowe,
US 2474497; Klein,
US 2474533 (both 1949 to Lake Chemical); Rowe,
US 2536096; Munn,
US 2670273 (1951, 1954 both to Mountain Copper); by treatment of Cu(OH)2 with SO2: Rowe,
US 2665192 (1954 to Mountain Chemical); or by electrolysis of an aq soln of NaCl between Cu electrodes: Arend,
Paint Technol. 13, 265 (1948). Laboratory prepns: Glemser, Sauer in
Handbook of Preparative Inorganic Chemistry vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) p 1011. Toxicity study: H. F. Smyth
et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969).
Properties: Cubic crystals or microcrystalline powder. Color may be yellow, red, or brown depending on the method of prepn and the particle size. Stable in dry air; gradually oxidizes in moist air to CuO. mp 1232°; d425 6.0. Practically insol in water. Sol in NH4OH; in HCl forming CuCl which dissolves in excess HCl. With dil H2SO4 or dil HNO3, the cupric salt is formed and half the copper is pptd as the metal. LD50 orally in rats: 0.47 g/kg (Smyth).
Melting point: mp 1232°
Density: d425 6.0
Toxicity data: LD50 orally in rats: 0.47 g/kg (Smyth)
Use: Fungicide; antiseptic for fishnets; in antifouling paints for marine use; in photoelectric cells; as red pigment for glass, ceramic glazes; in brazing pastes; in rectifiers; as catalyst.
