Copper(II) oxide

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Copper(II) oxide
200px
200px
200px
Names
IUPAC name
Copper(II) oxide
Other names
Cupric oxide
Identifiers
1317-38-0 YesY
ChEMBL ChEMBL1909057 N
ChemSpider 144499 YesY
Jmol 3D model Interactive image
Interactive image
PubChem 14829
RTECS number GL7900000
UNII V1XJQ704R4 YesY
  • InChI=1S/Cu.O/q+2;-2 YesY
    Key: KKCXRELNMOYFLS-UHFFFAOYSA-N YesY
  • InChI=1/Cu.O/rCuO/c1-2
    Key: QPLDLSVMHZLSFG-PHEGLCPBAN
  • InChI=1/Cu.O/q+2;-2
    Key: KKCXRELNMOYFLS-UHFFFAOYAT
  • [Cu]=O
  • [Cu+2].[O-2]
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
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
43 J·mol−1·K−1
−156 kJ·mol−1
Vapor pressure {{{value}}}
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 verify (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. 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.[2]

Production

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

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

2 Cu(NO3)2 → 2 CuO + 4 NO2 + O2
Cu(OH)2 (s) → CuO (s) + H2O (l)
CuCO3 → CuO + CO2


Reactions

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:

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]

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

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.[1]

The work function of bulk CuO is 5.3eV[3]

Copper(II) oxide is a p-type semiconductor, with a narrow band gap of 1.2 eV. Cupric oxide can be used to produce dry cell batteries. It could also been used in wet cell batteries as the cathode, with lithium as an anode, and dioxalane mixed with lithium perchlorate as the electrolyte.

Uses

As a significant product of copper mining, copper(II) oxide is the starting point for the production of other copper salts. For example, many wood preservatives are produced from copper oxide.[2]

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 as a dietary supplement in animals.[4]

It is also used when welding with copper alloys.[5]

Use in disposal

Cupric oxide can be used to safely dispose of hazardous materials such as cyanide, hydrocarbons, halogenated hydrocarbons and dioxins, through oxidation.[6]

The decomposition of phenol and pentachlorophenol follow these pathways:

C6H5OH + 14CuO → 6CO2 + 3H2O + 14Cu
C6Cl5OH + 2H2O + 9CuO → 6CO2 + 5HCl + 9Cu

See also

References

  1. 1.0 1.1 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°.
  2. 2.0 2.1 H. Wayne Richardson "Copper Compounds in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a07_567
  3. Lua error in package.lua at line 80: module 'strict' not found.
  4. Lua error in package.lua at line 80: module 'strict' not found.
  5. Lua error in package.lua at line 80: module 'strict' not found.
  6. Lua error in package.lua at line 80: module 'strict' not found.

External links