COPPER(II) OXIDE* - (1317-38-0)


Name: copper(II) oxide*; cupric oxide
CAS Number: 1317-38-0
Chemical Formula: CuO
Molar Mass: 79.5454 g
State of Matter: black powder
Mass Percent: Cu 79.886 %; O 20.113 % 


• inorganic


• "As pigment in glass, ceramics, enamels, porcelain glazes, artificial gems; in manuf[acture] of rayon, other Cu comp[oun]ds; in sweetening petr[oleum] gases; in galvanic electrodes; as flux in Cu metallurgy; in correcting Cu deficiencies in soil; as optical-glass polishing agent; to impart flux-and abrasion-resistance to glass fibers; in antifouling paints, pyrotechnic compositions; welding fluxes for bronze; as exciter in phosphor mixtures; as catalyst for organic reactions." 1

• "Throughout recorded history, copper(II) oxide has been used as a pigment to color ceramics, enamels, porcelain glazes, and artificial gems, applications that continue to the present day. The oxide adds a bluish to greenish tint to such materials. Copper(II) oxide also finds use as an insecticide and fumigant. It is used primarily in the treatment of potato plants and as an antifouling agent on boat hulls. An antifouling agent is a material that prevents the formation of barnacles and other organisms on the bottom of the boat. When such organisms grow on a boat's hull, they increase the friction produced when the boat rides through the water, thus reducing its speed. The compound is also used as a wood preservative, to protect fence posts, pilings, decking, roofing, shingles, sea walls, and other freshwater and marine structures from insects and fungi.

Other uses to which copper(II) oxide is put include the following:
• In the preparation of superconducting materials, materials that have essentially no resistance to the flow of electric current;
• In the manufacture of batteries and electrodes;
• As a welding flux for use with bronze objects and materials;
• For polishing of optical glass used in telescopes, microscopes, and similar instruments;
• In the preparation of phosphors, materials that glow in the dark after being exposed to light;
• For the removal of sulfur and sulfur compounds for petroleum;
• In the manufacture of rayon;
• As a catalyst in many industrial and commercial chemical reactions." 2

Physical Properties

Melting Point:*
1446°C 3 = 1719.15 K = 2634.8°F

Density (g/cm3):
6.31 at room temperature/pressure 3
* - 1 atm pressure


insoluble:  • 3
soluble:  3


Bonding: polar covalent
Ionic Character: 46.67 %


ΔHf° (s): -37.6 kcal/mol 4 = -157.32 kJ/mol
S° (s): 10.19 cal/(mol•K) 5 = 42.63 J/(mol•K)
ΔGf° (s): -31.0 kcal/mol 6 = -129.70 kJ/mol


Safety Information

NFPA 704 Ratings:
Health: 2 - Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury.
Flammability: 0 - Will not burn.
Reactivity: 1 - Normally stable, but can become unstable at elevated temperatures and pressures.

For More Information


(1) - The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 13th ed.; Budavari, S.; O'Neil, M.J.; Smith, A.; Heckelman, P. E.; Kinneary, J. F., Eds.; Merck & Co.: Whitehouse Station, NJ, 2001; entry 2674.
(2) - Schlager, Neil, Weisblatt, Jayne, Newton, David E., and Montney, Charles B. Chemical Compounds Vol. 1; Thomson-Gale: Detroit, MI, 2006; pp 247-249.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4-56.
(4) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(6) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(7) - Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 97.
(8) - Zumdahl, Steven and Zumdahl, Susan A. Chemistry 9th ed.; Brooks/Cole: Belmont, CA, 2014; p 132.