2519. Copper

Nomenclature

CAS number: 7440-50-8

Description and references

Cu; at. wt 63.546; at. no. 29; valences 1, 2. Group IB (11). Occurrence in the earth's crust: 70 ppm; also present in seawater: 0.001-0.02 ppm. Two naturally occurring isotopes: 63 (69.09%), 65 (30.91%); nine artificial isotopes: 58-62, 64, 66-68. One of the earliest known metals. Found in nature in its native state; also in combined form in several minerals including chalcopyrite, q.v., chalcocite, bornite, (Cu5FeS4), tetrahedrite (Cu12Sb4S13), enargite (Cu3AsS4), antlerite (Cu3H4O8S). Extraction from ores: Clark-Hawley, Encyclopedia of Chemistry (Reinhold, New York, 2nd ed., 1966) p 288. Metallurgy of copper and its alloys: Metals Reference Book vols. 1, 2, C. J. Smithells, Ed. (Butterworth's, London, 3rd ed., 1962). A trace element essential to many plants and animals. Occurs in biological complexes such as pheophytin (analog of chlorophyll), hemocyanin, tyrosinase and ceruloplasmin, q.q.v. Reviews of copper and copper compounds: ACS Monograph Series no. 122, entitled “Copper,” A. Butts, Ed. (Reinhold, New York, 1954) 936 pp; Massey, “Copper” in Comprehensive Inorganic Chemistry vol. 3, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 1-78; W. M. Tuddenham, P. A. Dougall, Kirk-Othmer Encyclopedia of Chemical Technology vol. 6 (Wiley-Interscience, New York, 3rd ed., 1979) pp 819-869. Book: Inflammatory Diseases and Copper, J. R. J. Sorenson, Ed. (Humana Press, Clifton, NJ, 1982) 622 pp. Review of role in human diseases: G. J. Brewer, Curr. Opin. Chem. Biol. 7, 207-212 (2003); of toxicology and human exposure: Toxicological Profile for Copper (PB2004-107333, 2004) 318 pp.

Properties

Reddish, lustrous, ductile, malleable metal; face-centered cubic structure; commercially available in the form of ingots, sheets, wire or powder. Becomes dull when exposed to air. In moist air gradually becomes coated with green basic carbonate. d 8.94. mp 1083°. bp 2595°. Mohs' hardness 3.0. Resistivity 1.673 microohm-cm. Heat of fusion 48.9 cal/g; heat of vaporization 1150 cal/g. Heat capacity at constant pressure (solid) 0.092 cal/g/°C (20°), (liq) 0.112 cal/g/°C. E0 (aq) Cu+/Cu +0.521 V; E0 (aq) Cu2+/Cu +0.337 V. Very slowly attacked by cold hydrochloric or dil sulfuric acid; readily by dil nitric acid, and by both hot concd H2SO4 and HBr. It is also attacked by acetic and other organic acids. Slowly sol in ammonia water. Water-soluble cupric salts yield with sodium hydroxide a bluish-green precipitate of cupric hydroxide which is changed to black cupric oxide on warming. Potassium ferrocyanide produces a brownish-red precipitate of copper ferrocyanide. Hydrogen sulfide produces in acid solns a black precipitate of cupric sulfide which is sol in soln of sodium cyanide. Aluminum, iron or zinc precipitate metallic copper from its solns.

Caution

Potential symptoms of overexposure to dusts and mists are irritation of eyes, nose, pharynx; nasal perforation; metallic taste; dermatitis. Potential symptoms of overexposure to fumes are irritation of eyes, upper respiratory system; metal fume fever (chills, muscle aches, nausea, fever; dry throat, cough, weakness, lassitude); metallic or sweet taste; discoloration of skin and hair. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 76.

Use

Manuf bronzes, brass, other copper alloys, electrical conductors, ammunition, copper salts, works of art. Catalyst. Absorption of oxygen.