| IUPAC name
| Other names
|3D model (Jmol)|| Interactive image|
|Molar mass||79.545 g/mol|
|Appearance||black to brown powder|
|Melting point||1,326 °C (2,419 °F; 1,599 K)|
|Boiling point||2,000 °C (3,630 °F; 2,270 K)|
|Solubility|| soluble in ammonium chloride, potassium cyanide |
insoluble in alcohol, ammonium hydroxide, ammonium carbonate
|Band gap||1.2 eV|
Refractive index (nD)
a = 4.6837, b = 3.4226, c = 5.1288
α = 90°, β = 99.54°, γ = 90°
Std enthalpy of
|Safety data sheet||Fischer Scientific|
EU classification (DSD)
| Harmful (Xn)|
Dangerous for the environment (N)
|US health exposure limits (NIOSH):|
|TWA 1 mg/m3 (as Cu)|
|TWA 1 mg/m3 (as Cu)|
IDLH (Immediate danger)
|TWA 100 mg/m3 (as Cu)|
| Nickel(II) oxide|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|(what is ?)|
Copper(II) oxide or cupric oxide is the inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O. As a mineral, it is known as tenorite and paramelaconite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds.
It is produced on a large scale by pyrometallurgy used to extract copper from ores. The ores are treated with an aqueous mixture of ammonium carbonate, ammonia, and oxygen to give copper(I) and copper(II) ammine complexes, which are extracted from the solids. These complexes are decomposed with steam to give CuO.
It can be formed by heating copper in air at around 300 - 800°C:
- 2 Cu + O2 → 2 CuO
- 2 Cu(NO3)2 → 2 CuO + 4 NO2 + O2
- Cu(OH)2 (s) → CuO (s) + H2O (l)
- CuCO3 → CuO + CO2
- CuO + 2 HNO3 → Cu(NO3)2 + H2O
- CuO + 2 HCl → CuCl2 + H2O
- CuO + H2SO4 → CuSO4 + H2O
It reacts with concentrated alkali to form the corresponding cuprate salts:
- 2 MOH + CuO + H2O → M2[Cu(OH)4]
- CuO + H2 → Cu + H2O
- CuO + CO → Cu + CO2
- 2CuO + C → 2Cu + CO2
When cupric oxide is substituted for iron oxide in thermite the resulting mixture is a low explosive, not an incendiary.
Structure and physical properties
Copper(II) oxide belongs to the monoclinic crystal system. The copper atom is coordinated by 4 oxygen atoms in an approximately square planar configuration.
Cupric oxide is used as a pigment in ceramics to produce blue, red, and green, and sometimes gray, pink, or black glazes.
It is also used when welding with copper alloys.
Use in disposal
The decomposition reactions of phenol and pentachlorophenol follow these pathways:
- C6H5OH + 14CuO → 6CO2 + 3H2O + 14Cu
- C6Cl5OH + 2H2O + 9CuO → 6CO2 + 5HCl + 9Cu
- The effect of hydrostatic pressure on the ambient temperature structure of CuO, Forsyth J.B., Hull S., J. Phys.: Condens. Matter 3 (1991) 5257-5261 , doi:10.1088/0953-8984/3/28/001. Crystallographic point group: 2/m or C2h. Space group: C2/c. Lattice parameters: a = 4.6837(5), b = 3.4226(5), c = 5.1288(6), α = 90°, β = 99.54(1)°, γ = 90°.
- "NIOSH Pocket Guide to Chemical Hazards #0150". National Institute for Occupational Safety and Health (NIOSH).
- H. Wayne Richardson "Copper Compounds in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a07_567
- F. P. Koffyberg and F. A. Benko (1982). "A photoelectrochemical determination of the position of the conduction and valence band edges of p-type CuO". J. Appl. Phys. 53 (2): 1173. doi:10.1063/1.330567.
- "Uses of Copper Compounds: Other Copper Compounds". Copper Development Association. 2007. Retrieved 2007-01-27.
- Cupric Oxide Should Not Be Used As a Copper Supplement for Either Animals or Humans, Baker, D. H., J. Nutr. 129, 12 (1999) 2278-2279
- "Cupric Oxide Data Sheet". Hummel Croton Inc. 2006-04-21. Retrieved 2007-02-01.
- Kenney, Charlie W.; Uchida, Laura A. (April 1986). "Use of copper (II) oxide as source of oxygen for oxidation reactions". Retrieved 2007-06-29.
|Wikimedia Commons has media related to Copper(II) oxide.|
- National Pollutant Inventory - Copper and compounds fact sheet
- Copper oxides project page
- CDC - NIOSH Pocket Guide to Chemical Hazards