Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It can be classified as a

coordination polymer Coordination may refer to: * Coordination (linguistics), a compound grammatical construction * Coordination complex, consisting of a central atom or ion and a surrounding array of bound molecules or ions ** A chemical reaction to form a coordinat ...

or a

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

. It consists of copper(II) bonded to

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

and

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It ...

with formula . It is a green solid that occurs in nature as the mineral

malachite Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often for ...

. It has been used since antiquity as a

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

, and it is still used as such in artist paints, sometimes called verditer, green bice, or mountain green. Sometimes basic copper carbonate refers to ()₂()₂, a blue crystalline solid also known as the mineral

azurite Azurite or '' Azure spar'Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0. ''(in Russian)'' is a soft, deep-blue copp ...

. It too has been used as pigment, sometimes under the name mountain blue or blue verditer. Both

and

can be found in the

verdigris Verdigris () is a common name for any of a variety of somewhat toxic copper salt (chemistry), salts of acetic acid, which range in colour from green to a blue-green, bluish-green depending on their chemical composition.H. Kühn, Verdigris and Cop ...

patina Patina ( or ) is a thin layer that variously forms on the surface of copper, brass, bronze, and similar metals and metal alloys ( tarnish produced by oxidation or other chemical processes), or certain stones and wooden furniture (sheen prod ...

that is found on weathered

brass Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. I ...

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals (such as phosphorus) or metalloid ...

, and

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

. The composition of the patina can vary, in a maritime environment depending on the environment a basic chloride may be present, in an urban environment basic sulfates may be present. This compound is often improperly called (even in chemistry articles) copper carbonate, cupric carbonate, and similar names. The true (neutral)

copper(II) carbonate Copper(II) carbonate or cupric carbonate is a chemical compound with formula . At ambient temperatures, it is an ionic solid (a salt) consisting of copper(II) cations and carbonate anions . This compound is rarely encountered because it is dif ...

CuCO₃ is not known to occur naturally. It is decomposed by water or moisture from the air. It was synthesized only in 1973 by high temperature and very high pressures.

Preparation

Basic copper carbonate is prepared by combining aqueous solutions of

copper(II) sulfate Copper(II) sulfate is an inorganic compound with the chemical formula . It forms hydrates , where ''n'' can range from 1 to 7. The pentahydrate (''n'' = 5), a bright blue crystal, is the most commonly encountered hydrate of copper(II) sulfate, whi ...

and

sodium carbonate Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water ...

. Basic copper carbonate precipitates from the solution, with release of

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

:Jack Reginald Irons Hepburn (1927): "The chemical nature of precipitated basic cupric carbonate". Article CCCLXXXVI, ''Journal of the Chemical Society'' (Resumed), volume 1927, pp. 2883–2896. : Basic copper carbonate can also be prepared by treating aqueous solutions of

with

sodium bicarbonate Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...

Copper(II) sulfate Copper(II) sulfate is an inorganic compound with the chemical formula . It forms hydrates , where ''n'' can range from 1 to 7. The pentahydrate (''n'' = 5), a bright blue crystal, is the most commonly encountered hydrate of copper(II) sulfate, whi ...

may also be substituted with

Copper(II) chloride Copper(II) chloride, also known as cupric chloride, is an inorganic compound with the chemical formula . The monoclinic crystal system, monoclinic yellowish-brown anhydrous form slowly absorbs moisture to form the orthorhombic blue-green hydrate, ...

Reactions

Basic copper carbonate is decomposed by acids, such as solutions of

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

, into the copper(II) salt and carbon dioxide. In 1794 the French chemist

Joseph Louis Proust Joseph Louis Proust (26 September 1754 – 5 July 1826) was a French chemist. He was best known for his discovery of the law of definite proportions in 1797, stating that chemical compounds always combine in constant proportions. Life Joseph-Lo ...

(1754–1826) thermally decomposed copper carbonate to CO₂ and CuO,

cupric oxide 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, or so ...

. The basic copper carbonates, malachite and azurite, both decompose forming H₂O, CO₂, and CuO,

Uses

Basic copper carbonate is used to remove thiols and hydrogen sulfide from some gas streams, a process called "sweetening". Like many other copper compounds, it also has been used as an

algaecide Algaecide or algicide is a biocide used for killing and preventing the growth of algae, often defined in a loose sense that, beyond the biological definition, also includes cyanobacteria ("blue-green algae"). An algaecide may be used for controlled ...

wood preservative Wood preservation refers to any method or process, or even technique, used to protect the wood and extend its service life. Most wood species are susceptible to both biological (''biotic'') and non-biological (''abiotic'') factors that cause d ...

and similar applications. It is a precursor to various catalysts and copper soaps. Both malachite and azurite, as well as synthetic basic copper carbonate have been used as

s. One example of the use of both

and its artificial form blue verditer is the portrait of the family of

Balthasar Gerbier Sir Balthazar Gerbier (23 February 1592, in N.S. – 1663) was an Anglo-Dutch courtier, diplomat, art advisor, miniaturist and architectural designer, in his own words fluent in "several languages" with "a good hand in writing, skill in sciences ...

Peter Paul Rubens Sir Peter Paul Rubens ( ; ; 28 June 1577 – 30 May 1640) was a Flemish painting, Flemish artist and diplomat. He is considered the most influential artist of the Flemish Baroque painting, Flemish Baroque tradition. Rubens' highly charged comp ...

. The green skirt of Deborah Kip is painted in

smalt Cobalt glass—known as "smalt" when ground as a pigment—is a deep blue coloured glass prepared by including a cobalt compound, typically cobalt oxide or cobalt carbonate, in a glass melt. Cobalt is a very intense colouring agent and very litt ...

, blue verditer (artificial form of azurite),

yellow ochre Ochre ( ; , ), iron ochre, or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the col ...

lead-tin-yellow Lead-tin yellow is a yellow pigment, of historical importance in oil painting, sometimes called the "Yellow of the Old Masters" because of the frequency with which it was used by those famous painters. Nomenclature The name lead-tin yellow is ...

and yellow lake. The green color is achieved by mixing blue and yellow pigments.Peter Paul Rubens, The Gerbier Family
ColourLex

References

External links

* ttp://colourlex.com/project/azurite/ Azuriteat ColourLex
Blue verditer
at ColourLex {{DEFAULTSORT:Copper(Ii) Carbonate Carbonates Copper(II) compounds Pyrotechnic colorants Hydroxides