Structural Formula Vector Image
Title: Zinc
CAS Registry Number: 7440-66-6
Literature References: Zn; at. wt 65.409; at. no. 30; valence 2. Group IIB (12). Essential nutritional trace element necessary for function of many metallogenzymes. Abundance in earth's crust: 0.02% by wt. Natural isotopes: 64 (48.89%); 66 (27.81%); 68 (18.57%); 67 (4.11%); 70 (0.62%); eight radioactive isotopes and two isomers. Occurs in smithsonite or zinc spar, sphalerite or zinc blende, zincite, willemite, franklinite, [(Zn,Mn,Fe)O.(Fe.Mn2)O3] or gahnite (ZnAl2O4). Has been known since very early times. Commercial forms: ingots; lumps; sheets; wire; shot; strips; sticks; granules; mossy; powder (dust). Prepn: Gowland, Bannister, Metallurgy of Non-Ferrous Metals (Griffin, London, 1930); Zinc Production, Properties and Uses (Zinc Development Association, London, 1968). Reviews: Zinc, C. H. Mathewson, Ed., A.C.S. Monograph Series no. 142 (Reinhold, New York, 1959) 721 pp; Schlechter, Thompson, "Zinc and Zinc Alloys" in Kirk-Othmer Encyclopedia of Chemical Technology vol. 22 (Interscience, New York, 2nd ed., 1970) pp 555-603; Aylett, "Group IIB" in Comprehensive Inorganic Chemistry vol. 3, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 187-328. Review of toxicology and human exposure: Toxicological Profile for Zinc (PB2006-100008, 2005) 352 pp.
Properties: Bluish-white, lustrous metal; distorted hexagonal close-packed structure; stable in dry air; becomes covered with a white coating of basic carbonate on exposure to moist air. mp 419.5°. bp 908°. d25 7.14. Heat capacity at constant pressure (25°): 6.07 cal/mole deg. Mohs' hardness 2.5. When heated to 100-150° becomes malleable, at 210° becomes brittle and pulverizable. Burns in air with a bluish-green flame. Loses electrons in aqueous systems to form Zn2+ E° (aq) Zn/Zn2+ 0.763 V. Slowly attacked by H2SO4 or HCl; oxidizing agents or metal ions, e.g. Cu2+, Ni2+, Co2+, accelerate the process. Reacts slowly with ammonia water and acetic acid; rapidly with HNO3. Reacts with alkali hydroxides to form "zincates", ZnO22-, which are actually hydroxo complexes such as Zn(OH)3-; Zn(OH)42-, [Zn(OH)4(H2O)2]2-.
Melting point: mp 419.5°
Boiling point: bp 908°
Density: d25 7.14
CAUTION: Potential symptoms of overexposure by fume inhalation are metal fume fever; by acute oral overexposure are stomach cramps, nausea, vomiting; by chronic oral overexposure are anemia, pancreatic damage, decreased HDL cholesterol levels (PB2006-100008).
Use: Galvanizing sheet iron; as ingredient of alloys such as bronze, brass, Babbitt metal, German silver, and special alloys for die-casting; as a protective coating for other metals to prevent corrosion; for electrical apparatus, especially dry cell batteries, household utensils, castings, printing plates, building materials, railroad car linings, automotive equipment; as reducing agent in organic chemistry; for deoxidizing bronze; extracting gold by the cyanide process, purifying fats for soaps; bleaching bone glue; manuf sodium hydrosulfite; insulin zinc salts; as reagent in analytical chemistry, e.g., in the Marsh and Gutzeit test for arsenic; as a reducer in the determination of iron. It is a nutritional trace element.

Other Monographs:
Tungstic(VI) AcidTung Oil4-Amino-3-hydroxybutyric AcidTriamcinolone Benetonide
FlumetramideDalfopristinPrephenic AcidCatalposide
ActinodaphnineAluminum NitrideProtoveratrinesMetrizoic Acid
©2006-2020 DrugFuture->Chemical Index Database