Copper(II) oxide

Last updated
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 (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.013.882 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 215-269-1
PubChem CID
RTECS number
  • GL7900000
UNII
  • InChI=1S/Cu.O/q+2;-2 Yes check.svgY
    Key: KKCXRELNMOYFLS-UHFFFAOYSA-N Yes check.svgY
  • 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
Appearanceblack 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 carbonate
Band gap 1.2  eV
+238.9·10−6 cm3/mol
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
(S298)
43 J·mol−1·K−1
−156 kJ·mol−1
Hazards
GHS labelling:
GHS-pictogram-pollu.svg
Warning
H410
P273, P391, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
0
1
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
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).
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Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds. [3]

Contents

Production

It is produced on a large scale by pyrometallurgy, as one stage in extracting copper from its 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 basic copper(II) carbonate: [4]

2 Cu(NO3)2(s) → 2 CuO(s) + 4 NO2(g) + O2(g) (180°C)
Cu2(OH)2CO3(s) → 2 CuO(s) + CO2(g) + H2O(g)
Cu(OH)2(s)CuO(s) + H2O(g) [5]

Reactions

Copper(II) oxide dissolves in mineral acids such as hydrochloric acid, sulfuric acid or nitric acid to give the corresponding copper(II) salts: [4]

CuO + 2 HNO3 → Cu(NO3)2 + H2O
CuO + 2 HCl → CuCl2 + H2O
CuO + H2SO4 → CuSO4 + H2O

In presense of water It reacts with concentrated alkali to form the corresponding cuprate salts:

2 MOH + CuO + H2O → M2[Cu(OH)4]
2 NaOH + CuO + H2O → Na2[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
2 CuO + 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 5.3 eV [6]

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. [3]

Cupric oxide is used as a pigment in ceramics to produce blue, red, and green, and sometimes gray, pink, or black glazes.

It is incorrectly used as a dietary supplement in animal feed. [7] Due to low bioactivity, negligible copper is absorbed. [8]

It is used when welding with copper alloys. [9]

A copper oxide electrode formed part of the early battery type known as the Edison–Lalande cell. Copper oxide was also used in a lithium battery type (IEC 60086 code "G").

Pyrotechnics and fireworks

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.

Similar compounds

An example of natural copper(I,II) oxide is the mineral paramelaconite, Cu+2Cu2+2O3. [10] [11]

See also

Related Research Articles

<span class="mw-page-title-main">Nitric acid</span> Highly corrosive mineral acid

Nitric acid is the inorganic compound with the formula HNO3. It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% HNO3, it is referred to as fuming nitric acid. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.

<span class="mw-page-title-main">Oxide</span> Chemical compound where oxygen atoms are combined with atoms of other elements

An oxide is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– ion with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 that protects the foil from further oxidation.

In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions.

<span class="mw-page-title-main">Iron(III) oxide</span> Chemical compound

Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main source of iron for the steel industry. Fe2O3 is readily attacked by acids. Iron(III) oxide is often called rust, since rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as hydrous ferric oxide.

<span class="mw-page-title-main">Basic copper carbonate</span> Chemical compound

Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It is an ionic compound consisting of the ions copper(II) Cu2+
, carbonate CO2−
3
, and hydroxide OH
.

<span class="mw-page-title-main">Copper(I) oxide</span> Chemical compound – an oxide of copper with formula Cu2O

Copper(I) oxide or cuprous oxide is the inorganic compound with the formula Cu2O. It is one of the principal oxides of copper, the other being copper(II) oxide or cupric oxide (CuO). Cuprous oxide is a red-coloured solid and is a component of some antifouling paints. The compound can appear either yellow or red, depending on the size of the particles. Copper(I) oxide is found as the reddish mineral cuprite.

<span class="mw-page-title-main">Copper(II) nitrate</span> Chemical compound

Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Cu(NO3)2(H2O)x. The hydrates are blue solids. Anhydrous copper nitrate forms blue-green crystals and sublimes in a vacuum at 150-200 °C. Common hydrates are the hemipentahydrate and trihydrate.

<span class="mw-page-title-main">Chromate and dichromate</span> Chromium(VI) anions

Chromate salts contain the chromate anion, CrO2−
4
. Dichromate salts contain the dichromate anion, Cr
2
O2−
7
. They are oxyanions of chromium in the +6 oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible.

Cuprates are a class of compounds that contain copper (Cu) atom(s) in an anion. They can be broadly categorized into two main types:

<span class="mw-page-title-main">Barium nitrate</span> Chemical compound

Barium nitrate is the inorganic compound with the chemical formula Ba(NO3)2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics.

<span class="mw-page-title-main">Copper(II) chloride</span> Chemical compound

Copper(II) chloride, also known as cupric chloride, is an inorganic compound with the chemical formula CuCl2. The monoclinic yellowish-brown anhydrous form slowly absorbs moisture to form the orthorhombic blue-green dihydrate CuCl2·2H2O, with two water molecules of hydration. It is industrially produced for use as a co-catalyst in the Wacker process.

<span class="mw-page-title-main">Vanadium(V) oxide</span> Precursor to vanadium alloys and industrial catalyst

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.

<span class="mw-page-title-main">Copper(II) hydroxide</span> Hydroxide of copper

Copper(II) hydroxide is the hydroxide of copper with the chemical formula of Cu(OH)2. It is a pale greenish blue or bluish green solid. Some forms of copper(II) hydroxide are sold as "stabilized" copper(II) hydroxide, although they likely consist of a mixture of copper(II) carbonate and hydroxide. Cupric hydroxide is a strong base, although its low solubility in water makes this hard to observe directly.

<span class="mw-page-title-main">Copper(II) acetate</span> Chemical compound

Copper(II) acetate, also referred to as cupric acetate, is the chemical compound with the formula Cu(OAc)2 where AcO is acetate (CH
3
CO
2
). The hydrated derivative, Cu2(OAc)4(H2O)2, which contains one molecule of water for each copper atom, is available commercially. Anhydrous copper(II) acetate is a dark green crystalline solid, whereas Cu2(OAc)4(H2O)2 is more bluish-green. Since ancient times, copper acetates of some form have been used as fungicides and green pigments. Today, copper acetates are used as reagents for the synthesis of various inorganic and organic compounds. Copper acetate, like all copper compounds, emits a blue-green glow in a flame.

In chemical nomenclature, the IUPAC nomenclature of inorganic chemistry is a systematic method of naming inorganic chemical compounds, as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in Nomenclature of Inorganic Chemistry. Ideally, every inorganic compound should have a name from which an unambiguous formula can be determined. There is also an IUPAC nomenclature of organic chemistry.

In ore deposit geology, supergene processes or enrichment are those that occur relatively near the surface as opposed to deep hypogene processes. Supergene processes include the predominance of meteoric water circulation (i.e. water derived from precipitation) with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary (hypogene) sulfide ore minerals and redistribute the metallic ore elements. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, and react with hypogene sulfides at the supergene-hypogene boundary. The reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is particularly noted in copper ore deposits where the copper sulfide minerals chalcocite (Cu2S), covellite (CuS), digenite (Cu18S10), and djurleite (Cu31S16) are deposited by the descending surface waters.

<span class="mw-page-title-main">Copper(II) phosphate</span> Chemical compound

Copper(II) phosphate are inorganic compounds with the formula Cu3(PO4)2. They can be regarded as the cupric salts of phosphoric acid. Anhydrous copper(II) phosphate and a trihydrate are blue solids.

<span class="mw-page-title-main">Dicopper chloride trihydroxide</span> Chemical compound

Dicopper chloride trihydroxide is the chemical compound with the formula Cu2(OH)3Cl. It is often referred to as tribasic copper chloride (TBCC), copper trihydroxyl chloride or copper hydroxychloride. It is a greenish crystalline solid encountered in mineral deposits, metal corrosion products, industrial products, art and archeological objects, and some living systems. It was originally manufactured on an industrial scale as a precipitated material used as either a chemical intermediate or a fungicide. Since 1994, a purified, crystallized product has been produced at the scale of thousands of tons per year, and used extensively as a nutritional supplement for animals.

<span class="mw-page-title-main">Lead compounds</span> Type of compound

Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.

<span class="mw-page-title-main">Transition metal nitrate complex</span> Compound of nitrate ligands

A transition metal nitrate complex is a coordination compound containing one or more nitrate ligands. Such complexes are common starting reagents for the preparation of other compounds.

References

  1. 1 2 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. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 Richardson, H. Wayne (2002). "Copper Compounds". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a07_567. ISBN   978-3527306732.
  4. 1 2 O. Glemser and H. Sauer (1963). "Copper, Silver, Gold". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press.
  5. Cudennec, Yannick; Lecerf, André (November 2003). "The transformation of Cu(OH)2 into CuO, revisited" (PDF). Solid State Sciences. 5 (11–12): 1471–1474. Bibcode:2003SSSci...5.1471C. doi:10.1016/j.solidstatesciences.2003.09.009. S2CID   96363475.
  6. 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. Bibcode:1982JAP....53.1173K. doi:10.1063/1.330567.
  7. "Uses of Copper Compounds: Other Copper Compounds". Copper Development Association. 2007. Archived from the original on 2013-08-15. Retrieved 2007-01-27.
  8. 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
  9. "Cupric Oxide Data Sheet". Hummel Croton Inc. 2006-04-21. Archived from the original on 2011-07-07. Retrieved 2007-02-01.
  10. "Paramelaconite".
  11. "List of Minerals". 21 March 2011.