Copper(II) sulfate
Overview
 
Copper sulfate, also known as cupric sulfate, is the chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Cu
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

SO4
Sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...

. This salt exists as a series of compounds that differ in their degree of hydration
Water of crystallization
In crystallography, water of crystallization or water of hydration or crystallization water is water that occurs in crystals. Water of crystallization is necessary for the maintenance of crystalline properties, but capable of being removed by sufficient heat...

. The anhydrous
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

 form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue. Copper sulfate exothermically
Exothermic reaction
An exothermic reaction is a chemical reaction that releases energy in the form of light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:-Overview:...

 dissolves in water to give the aquo complex
Metal aquo complex
Metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorates. They have the general stoichiometry [Mn]z+. Their behavior...

 [Cu(H2O)6]2+, which has octahedral molecular geometry
Octahedral molecular geometry
In chemistry, octahedral molecular geometry describes the shape of compounds where in six atoms or groups of atoms or ligands are symmetrically arranged around a central atom, defining the vertices of an octahedron...

 and is paramagnetic.
Encyclopedia
Copper sulfate, also known as cupric sulfate, is the chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Cu
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

SO4
Sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...

. This salt exists as a series of compounds that differ in their degree of hydration
Water of crystallization
In crystallography, water of crystallization or water of hydration or crystallization water is water that occurs in crystals. Water of crystallization is necessary for the maintenance of crystalline properties, but capable of being removed by sufficient heat...

. The anhydrous
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

 form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue. Copper sulfate exothermically
Exothermic reaction
An exothermic reaction is a chemical reaction that releases energy in the form of light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:-Overview:...

 dissolves in water to give the aquo complex
Metal aquo complex
Metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorates. They have the general stoichiometry [Mn]z+. Their behavior...

 [Cu(H2O)6]2+, which has octahedral molecular geometry
Octahedral molecular geometry
In chemistry, octahedral molecular geometry describes the shape of compounds where in six atoms or groups of atoms or ligands are symmetrically arranged around a central atom, defining the vertices of an octahedron...

 and is paramagnetic. Other names for copper(II) sulfate are "blue vitriol" and "bluestone".

Preparation and occurrence

Copper sulfate is produced industrially by treating copper metal or its oxides with sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

. For laboratory use, copper sulfate is usually purchased.

The anhydrous form occurs as a rare mineral known as chalcocyanite. The hydrated copper sulfate occurs in nature as chalcanthite
Chalcanthite
Chalcanthite, whose name derives from the Greek, chalkos and anthos, meaning copper flower, is a richly-colored blue/green water-soluble sulfate mineral CuSO4·5H2O. It is commonly found in the late-stage oxidation zones of copper deposits...

 (pentahydrate), and two more rare ones: bonattite (trihydrate) and boothite (heptahydrate).

Chemical properties

Copper(II) sulfate pentahydrate decomposes
Chemical decomposition
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...

 before melting at 150 °C, losing two water molecules at 63 °C, followed by two more at 109 °C and the final water molecule at 200 °C.

Dehydration proceeds by decomposition of the tetraaquacopper(2+) moiety, two opposing aqua groups are lost to give a diaquacopper(2+) moiety. The second dehydration step occurs with the final two aqua groups are lost. Complete dehydration occurs when the only unbound water molecule is lost.

At 650 °C, copper(II) sulfate decomposes into copper(II) oxide
Copper(II) oxide
Copper oxide or cupric oxide is the higher oxide of copper. As a mineral, it is known as tenorite.-Chemistry:It is a black solid with an ionic structure which melts above 1200 °C with some loss of oxygen...

 (CuO) and sulfur trioxide
Sulfur trioxide
Sulfur trioxide is the chemical compound with the formula SO3. In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain. It is prepared on massive scales as a precursor to sulfuric acid.-Structure and bonding:Gaseous SO3 is a trigonal planar molecule of...

 (SO3).

Its blue color is due to water of hydration. When heated in an open flame the crystals are dehydrated and turn grayish-white.

Copper sulfate reacts with concentrated hydrochloric acid. In the reaction the blue solution of copper(II) turns green, due to the formation of tetrachlorocuprate(II):
Cu2+ + 4 Cl → CuCl42–


It also reacts with more reactive metals than copper (e.g. Mg, Fe, Zn, Al, Sn, Pb etc.):
CuSO4 + Zn
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 → ZnSO4
Zinc sulfate
Zinc sulfate is the inorganic compound with the formula ZnSO4 as well as any of three hydrates. It was historically known as "white vitriol". It is a colorless solid that is a common source of soluble zinc ions.-Production and reactivity:...

 + Cu
CuSO4 + Fe
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 → FeSO4 + Cu
CuSO4 + Mg
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 → MgSO4
Magnesium sulfate
Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...

 + Cu
CuSO4 + Sn
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...

 → SnSO4 + Cu
3 CuSO4 + 2 Al
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 → Al2(SO4)3
Aluminium sulfate
Aluminium sulfate, alternatively spelt aluminum sulfate, aluminium sulphate, or aluminum sulphate; is a chemical compound with the formula Al23...

 + 3 Cu


The copper formed is deposited on the surface of the other metal. The reaction stops when no free surface of the metal is present anymore.

As a herbicide, fungicide and pesticide

Copper sulfate pentahydrate is a fungicide
Fungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...

. However, some fungi are capable of adapting to elevated levels of copper ions. Mixed with lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...

 it is called Bordeaux mixture
Bordeaux mixture
Bordeaux mixture is a mixture of copper sulfate and slaked lime used as a fungicide in vineyards. It is used mainly to control garden, vineyard, nursery and farm infestations of fungi, primarily downy mildew which can result from infections of Plasmopara viticola. It was invented in the Bordeaux...

 and used to control fungus on grapes, melons, and other berries. Another application is Cheshunt compound, a mixture of copper sulfate and ammonium carbonate used in horticulture to prevent damping off in seedlings. Its use as a herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...

 is not agricultural, but instead for control of invasive aquatic plants and the roots of plants near pipes containing water. It is used in swimming pools as an algaecide. A dilute solution of copper sulfate is used to treat aquarium fish for parasitic infections, and is also used to remove snails from aquariums. Copper ions are highly toxic to fish, so care must be taken with the dosage. Most species of algae can be controlled with very low concentrations of copper sulfate. Copper sulfate inhibits growth of bacteria such as Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

.

For most of the twentieth century, chromated copper arsenate
Chromated copper arsenate
Chromated copper arsenate is a wood preservative used for timber treatment since the mid-1930s. It is a mix of chromium, copper and arsenic formulated as oxides or salts. It preserves the wood from decay fungi, wood attacking insects, including termites, and marine borers...

 (CCA) was the dominant type of wood preservation
Wood preservation
All measures that are taken to ensure a long life of wood fall under the definition wood preservation . Apart from structural wood preservation measures, there are a number of different preservatives and processes that can extend the life of wood, timber, wood structures or engineered wood...

 for uses other than deep driven pile
Deep foundation
A deep foundation is a type of foundation distinguished from shallow foundations by the depth they are embedded into the ground. There are many reasons a geotechnical engineer would recommend a deep foundation over a shallow foundation, but some of the common reasons are very large design loads, a...

s, utility pole
Utility pole
A utility pole is a pole used to support overhead power lines and various other public utilities, such as cable, fibre optic cable, and related equipment such as transformers and street lights. It can be referred to as a telephone pole, power pole, hydro pole, telegraph pole, or telegraph post,...

s, and railroad tie
Railroad tie
A railroad tie/railway tie , or railway sleeper is a rectangular item used to support the rails in railroad tracks...

s. To make pressure-treated wood, a large cylinder is filled with an aqueous chemical bath. Copper sulfate pentahydrate is dissolved in the water along with other additives prior to the lumber being placed inside the cylinder. When the cylinder is pressurized, the chemicals are absorbed by the wood, giving the wood fungicidal, insecticidal, and UV-light-reflecting properties that help preserve it.

Niche uses

Being a relatively benign and cheap reagent, copper(II) sulfate has attracted many niche applications over the centuries.

Analytical reagent

Several chemical tests utilize copper sulfate. It is used in Fehling's solution
Fehling's solution
Fehling's solution is a chemical test used to differentiate between water-soluble aldehyde and ketone functional groups, and as a test for monosaccharides. The test was developed by German chemist Hermann von Fehling in 1849.-Laboratory preparation:...

 and Benedict's solution to test for reducing sugar
Reducing sugar
A reducing sugar is any sugar that either has an aldehyde group or is capable of forming one in solution through isomerisation. This functional group allows the sugar to act as a reducing agent, for example in the Tollens' test or Benedict's test.-Chemistry:...

s, which reduce the soluble blue copper(II) sulfate to insoluble red copper(I) oxide
Copper(I) oxide
Copper oxide or cuprous oxide is the inorganic compound with the formula Cu2O. It is one of the principal oxides of copper. This red-coloured solid is a component of some antifouling paints. The compound can appear either yellow or red, depending on the size of the particles, but both forms...

. Copper(II) sulfate is also used in the Biuret reagent to test for proteins.

Copper sulfate is also used to test blood for anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

. The blood is tested by dropping it into a solution of copper sulfate of known specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...

 – blood which contains sufficient hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...

 sinks rapidly due to its density, whereas blood which does not, floats or sinks less rapidly.

In a flame test
Flame test
A flame test is a procedure used in chemistry to detect the presence of certain metal ions, based on each element's characteristic emission spectrum. The color of flames in general also depends on temperature; see flame color....

, its copper ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

s emit a deep blue-green light, much more blue than the flame test for barium
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with...

.

Organic synthesis

Copper sulfate is employed in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...

. The anhydrous salt catalyses the transacetyl
Acetyl
In organic chemistry, acetyl is a functional group, the acyl with chemical formula COCH3. It is sometimes represented by the symbol Ac . The acetyl group contains a methyl group single-bonded to a carbonyl...

ation in organic synthesis. The hydrated salt reacts with potassium permanganate
Potassium permanganate
Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4− ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely purple solutions, the...

 to give an oxidant for the conversion of primary alcohols.

Chemistry education

Copper sulfate is a commonly included chemical in children's chemistry set
Chemistry set
A chemistry set is an educational toy allowing the user to perform simple chemistry experiments. The best known such sets were produced by the A. C. Gilbert Company, an early and middle 20th century American manufacturer of educational toys...

s and is often used to grow crystals in school
School
A school is an institution designed for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is commonly compulsory. In these systems, students progress through a series of schools...

s and in copper plating
Copper plating
Copper plating is the process in which a layer of copper is deposited on the item to be plated by using an electric current.Three basic types of processes are commercially available based upon the complexing system utilized:...

 experiments. Because of its toxicity, it is not recommended for small children. Copper sulfate is often used to demonstrate an exothermic reaction
Exothermic reaction
An exothermic reaction is a chemical reaction that releases energy in the form of light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:-Overview:...

, in which steel wool
Steel wool
Steel wool, also known as wire wool, is a bundle of strands of very fine soft steel filaments, used in finishing and repairing work to polish wood or metal objects, and for cleaning household cookware....

 or magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 ribbon is placed in an aqueous solution
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...

 of CuSO4. It is used in school chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 courses to demonstrate the principle of mineral hydration
Mineral hydration
Mineral hydration is an inorganic chemical reaction where water is added to the crystal structure of a mineral, usually creating a new mineral, usually called a hydrate....

. The pentahydrate form, which is blue, is heated, turning the copper sulfate into the anhydrous form which is white, while the water that was present in the pentahydrate form evaporates. When water is then added to the anhydrous compound, it turns back into the pentahydrate form, regaining its blue color, and is known as blue copperas. Copper(II) sulfate pentahydrate can easily be produced by crystallization from solution as copper(II) sulfate is quite hydroscopic.

In an illustration of a "single metal replacement reaction," iron is submerged in a solution of copper sulfate. Upon standing, iron reacts, producing iron(II) sulfate
Iron(II) sulfate
Iron sulfate or ferrous sulfate is the chemical compound with the formula FeSO4. Known since ancient times as copperas and as green vitriol, the blue-green heptahydrate is the most common form of this material...

, and copper precipitates.
Fe + CuSO4 → FeSO4 + Cu

Medical

Copper sulfate was also used in the past as an emetic. It is now considered too toxic for this use. It is still listed as an antidote
Antidote
An antidote is a substance which can counteract a form of poisoning. The term ultimately derives from the Greek αντιδιδοναι antididonai, "given against"....

 in the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

's ATC code V03
ATC code V03
-V03AB Antidotes:-V03AB Antidotes:-V03AB Antidotes::V03AB01 Ipecacuanha:V03AB02 Nalorphine:V03AB03 Edetates:V03AB04 Pralidoxime:V03AB05 Prednisolone and promethazine:V03AB06 Thiosulfate:V03AB08 Sodium nitrite:V03AB09 Dimercaprol:V03AB13 Obidoxime...

.

Art

In 2008, the artist Roger Hiorns
Roger Hiorns
Roger Hiorns is a British artist. He was nominated for the Turner Prize in 2009.Hiorns was born in Birmingham. He attended the Bournville College of Art from 1991 to 1993, and Goldsmiths College in London from 1993 to 1996. He lives in London....

 filled an abandoned waterproofed council flat in London with 75,000 liters of copper sulfate solution. The solution was left to crystallize for several weeks before the flat was drained, leaving crystal-covered walls, floors and ceilings. The work is titled Seizure.

Toxicological effects

Copper sulfate is an irritant. The usual routes by which humans can receive toxic exposure to copper sulfate are through eye or skin contact, as well as by inhaling powders and dusts. Skin contact may result in itching or eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...

. Eye contact with copper sulfate can cause conjunctivitis
Conjunctivitis
Conjunctivitis refers to inflammation of the conjunctiva...

, inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 of the eyelid lining, ulceration
Corneal ulcer
A corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. It is very common in dogs and is sometimes seen in cats...

, and clouding of the cornea
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

.

Upon acute oral exposure, copper sulfate is only moderately toxic. According to studies, the lowest dose of copper sulfate that had a toxic impact on humans is 11 mg/kg. Because of its irritating effect on the gastrointestinal tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

, vomiting is automatically triggered in case of the ingestion of copper sulfate. However, if copper sulfate is retained in the stomach, the symptoms can be severe. After 1–12 grams of copper sulfate are swallowed, such poisoning signs may occur as a metallic taste in the mouth, burning pain in the chest, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, vomiting, headache, discontinued urination, which leads to yellowing of the skin. In case of copper sulfate poisoning, injury to the brain, stomach, liver, or kidneys may also occur.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK