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| Names | |
|---|---|
| IUPAC name Copper(II) oxide | |
| Other names Cupric oxide | |
| Identifiers | |
3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.013.882 |
| EC Number |
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| RTECS number |
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| UNII | |
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| Properties | |
| CuO | |
| Molar mass | 79.545 g/mol |
| Appearance | black to brown powder |
| Density | 6.315 g/cm3 |
| Melting point | 1,326 °C (2,419 °F; 1,599 K) |
| Boiling point | 2,000 °C (3,630 °F; 2,270 K) |
| insoluble | |
| Solubility | soluble inammonium chloride,potassium cyanide insoluble inalcohol,ammonium carbonate |
| Band gap | 1.2 eV |
| +238.9·10−6 cm3/mol | |
Refractive index (nD) | 2.63 |
| Structure | |
| monoclinic,mS8[1] | |
| C2/c, #15 | |
a = 4.6837,b = 3.4226,c = 5.1288 α = 90°, β = 99.54°, γ = 90° | |
| Thermochemistry | |
Std molar entropy(S⦵298) | 43 J·mol−1·K−1 |
Std enthalpy of formation(ΔfH⦵298) | −156 kJ·mol−1 |
| Hazards | |
| GHS labelling: | |
  | |
| Warning | |
| H302,H410,H412 | |
| P264,P270,P273,P301+P317,P330,P391,P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 1 mg/m3 (as Cu)[2] |
REL (Recommended) | TWA 1 mg/m3 (as Cu)[2] |
IDLH (Immediate danger) | TWA 100 mg/m3 (as Cu)[2] |
| Safety data sheet (SDS) | Fisher Scientific |
| Related compounds | |
Otheranions | Copper(II) sulfide |
Othercations | Nickel(II) oxide Zinc oxide |
Related compounds | Copper(I) oxide |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Copper(II) oxide orcupric oxide is aninorganic compound with the formula CuO. A black solid, it is one of the two stableoxides ofcopper, the other being Cu2O orcopper(I) oxide (cuprous oxide). As amineral, it is known astenorite, or sometimes black copper. It is a product ofcopper mining and the precursor to many other copper-containing products and chemical compounds.[3]
It is produced on a large scale bypyrometallurgy, as one stage in extracting copper from its ores. The ores are treated with an aqueous mixture ofammonium carbonate,ammonia, andoxygen to ultimately give copper(II)ammine complex carbonates, such as[Cu(NH3)4]CO3. After extraction from the residues and after separation from iron, lead, etc. impurities, the carbonate salt is decomposed with steam to give CuO.[3]
It can be formed by heating copper in air at around 300–800 °C:
For laboratory uses, copper(II) oxide is conveniently prepared by pyrolysis ofcopper(II) nitrate orbasic copper(II) carbonate:[4]
Dehydration of cupric hydroxide has also been demonstrated:
Copper(II) oxide reacts withmineral acids such ashydrochloric acid,sulfuric acid, andnitric acid to give the corresponding hydrated copper(II) salts:[4]
In presence of water it reacts with concentratedalkali to form the correspondingcuprate salts:
It can also be reduced tocopper metal usinghydrogen,carbon monoxide, andcarbon:
When cupric oxide is substituted for iron oxide inthermite the resulting mixture is a low explosive, not an incendiary.
Copper(II) oxide belongs to themonoclinic crystal system. The copper atom is coordinated by 4 oxygen atoms in an approximately square planar configuration.[1]
Thework function of bulk CuO is 5.3eV.[5]
As a significant product of copper mining, copper(II) oxide is the starting point for the production of many other copper salts. For example, manywood preservatives are produced from copper oxide.[3]
Cupric oxide is used as apigment in ceramics to produce blue, red, and green, and sometimes gray, pink, or black glazes.[3]
It is incorrectly used as a dietary supplement inanimal feed.[6] Due to low bioactivity, negligible copper is absorbed.[7]
It is used when welding withcopper alloys.[8]
A copper oxide electrode formed part of the early battery type known as theEdison–Lalande cell. Copper oxide was also used in alithium battery type (IEC 60086 code "G").
Used as moderate blue coloring agent in blue flame compositions with additional chlorine donors and oxidizers such as chlorates and perchlorates. Providing oxygen it can be used as flash powder oxidizer with metal fuels such as magnesium, aluminium, or magnalium powder. Sometimes it is used in strobe effects and thermite compositions as crackling stars effect.
An example ofnatural copper(I,II) oxide is the mineralparamelaconite, Cu+2Cu2+2O3.[9][10]
