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Cupric oxide

Copper(II) oxide
CopperIIoxide.jpg
Copper(II)-oxide-unit-cell-3D-balls.png
Copper(II)-oxide-3D-balls.png
Names
IUPAC name
Copper(II) oxide
Other names
Cupric oxide
Identifiers
3D model (Jmol)
ChEBI
ChemSpider
ECHA InfoCard 100.013.882
PubChem CID
RTECS number GL7900000
UNII
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 in ammonium chloride, potassium cyanide
insoluble in alcohol, ammonium hydroxide, ammonium carbonate
Band gap 1.2 eV
+238.9·10−6 cm3/mol
2.63
Structure
monoclinic, mS8
C2/c, #15
a = 4.6837, b = 3.4226, c = 5.1288
α = 90°, β = 99.54°, γ = 90°
Thermochemistry
43 J·mol−1·K−1
−156 kJ·mol−1
Hazards
Safety data sheet Fischer Scientific
Harmful (Xn)
Dangerous for the environment (N)
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Non-flammable
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 1 mg/m3 (as Cu)
REL (Recommended)
TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)
TWA 100 mg/m3 (as Cu)
Related compounds
Other anions
Copper(II) sulfide
Other cations
Nickel(II) oxide
Zinc oxide
Related compounds
Copper(I) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

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 or cuprous oxide. 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:

For laboratory uses, pure copper(II) oxide is better prepared by heating copper(II) nitrate, copper(II) hydroxide or copper(II) carbonate:


Copper(II) oxide is an amphoteric oxide, so it dissolves in mineral acids such as hydrochloric acid, sulfuric acid or nitric acid to give the corresponding copper(II) salts:

It reacts with concentrated alkali to form the corresponding cuprate salts:

It can also be reduced to copper metal using hydrogen, carbon monoxide, or carbon:

When cupric oxide is substituted for iron oxide in thermite the resulting mixture is a low explosive, not an incendiary.

Copper(II) oxide belongs to the monoclinic crystal system. The copper atom is coordinated by 4 oxygen atoms in an approximately square planar configuration.


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Wikipedia

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