Zinc chloride
General
Systematic name	Zinc chloride
Other names	Zinc(II) chloride, zinc dichloride, butter of zinc
Molecular formula	ZnCl2
Molar mass	136.29 g/mol
Appearance	White crystalline solid.
CAS number	[7646-85-7]
Properties
Density and phase	2.907 g/cm3, solid
Solubility in water	432 g/100 ml (25°C)
in ethanol	100 g/100 ml (12.5°C)
in acetone, diethyl ether	Soluble.
Melting point	275°C (548 K)
Boiling point	756°C (1029 K)
Structure
Coordination geometry	Tetrahedral, 4-coordinate, linear in the gas phase.
Crystal structure	Four forms known Hexagonal close-packed (δ) is the only stable form when anhydrous.
Dipole moment	? D
Hazards
MSDS	External MSDS
EU classification	Irritant (I), Corrosive(C).
NFPA 704
R-phrases	R34, R50, R53
S-phrases	S7/8, S28, S45, S60, S61
RTECS number	ZH1400000
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Zinc fluoride, zinc bromide, zinc iodide
Other cations	Copper(II) chloride, cadmium chloride
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Zinc chloride (ZnCl₂) is a colorless or white compound of zinc and chlorine that is extremely hygroscopic. Download high resolution version (759x663, 66 KB)Hydrated zinc chloride This image has been released into the public domain by its creator and original copyright holder. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... Water has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless chemical compound, one of the alcohols that is most often found in alcoholic beverages. ... R-phrases , , , S-phrases , , , Flash point -20 °C Autoignition temperature 465 °C RTECS number AL31500000 Supplementary data page Structure & properties n, εr, etc. ... Flash point -45 °C Autoignition temperature 170 °C R/S statement RTECS number KI5775000 Supplementary data page Structure and properties n, εr, etc. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... A tetrahedron (plural: tetrahedra) is a polyhedron composed of four triangular faces, three of which meet at each vertex. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Close-packing of spheres refers to arranging an infinite lattice of spheres so that they take up the greatest possible fraction of an infinite 3-dimensional space. ... The Earths magnetic field, which is approximately a dipole. ... The debye (symbol: D) is a non-SI and non-CGS unit of electrical dipole moment. ... A material safety data sheet or MSDS is a form containing data regarding the properties of a particular substance. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main source of European Union law concerning chemical safety. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... The dielectric constant εr (represented as or K in some cases) is defined as the ratio: where εs is the static permittivity of the material in question, and ε0 is the vacuum permittivity. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... IR spectrum of a thin film of liquid ethanol. ... Nuclear Magnetic Resonance Spectroscopy most commonly known as NMR Spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei. ... It has been suggested that Mass spectrum be merged into this article or section. ... // An ion is an atom, group of atoms, or subatomic particle with a net electric charge. ... Zinc fluoride (ZnF2) is an inorganic chemical compound. ... Zinc Bromide is a white ionic solid which is used in organic chemistry as a lewis acid. ... Zinc iodide is composed of Zinc and Iodine. ... // An ion is an atom, group of atoms, or subatomic particle with a net electric charge. ... Copper(II) chloride is the higher chloride of copper, with the formula CuCl2. ... Cadmium chloride is a white crystalline compound of cadmium and chlorine, with the formula CdCl2. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... Chlorine is the current Good Article Collaboration of the week! Please help to improve this article to the highest of standards. ... A hygroscopic substance is a substance that absorbs water readily from its surroundings. ...

Four crystalline structures have been reported, although in pure form (i.e. water-free) only the delta (hexagonal close-packed) phase can form. It can be quenched from the melt to form a glassy material.

Concentrated aqueous solutions of zinc chloride have the interesting property of dissolving starch, silk and cellulose, so that solutions cannot be filtered through standard filter papers. Starch is a complex carbohydrate which is insoluble in water, it is used by plants as a way to store excess glucose. ... Silk weaver Silk is a natural protein fiber that can be woven into textiles. ... Cellulose (C6H10O5)n is a long-chain polymeric polysaccharide carbohydrate, of beta-glucose. ...

Zinc chloride finds wide application in textile processing, metallurgical fluxes and chemical synthesis. To meet Wikipedias quality standards, this article or section may require cleanup. ... In metallurgy, flux is a substance which facilitates soldering, brazing, and welding by chemically cleaning the metals to be joined. ...

Chemical properties

Zinc chloride is an ionic salt, though some covalent character is indicated by its low melting point (275°C) and its high solubility in solvents such as diethyl ether. It behaves as a mild Lewis acid, and aqueous solutions have a pH around 4. It is hydrolyzed to an oxychloride when hydrated forms are heated. // An ion is an atom, group of atoms, or subatomic particle with a net electric charge. ... A magnified crystal of a salt (halite/sodium chloride) In chemistry, a salt is any ionic compound composed of positively charged cations and negatively charged anions so that the product is neutral and without a net charge. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... Flash point -45 °C Autoignition temperature 170 °C R/S statement RTECS number KI5775000 Supplementary data page Structure and properties n, εr, etc. ... In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ... The correct title of this article is pH. The initial letter is capitalized due to technical restrictions. ...

In aqueous solution, zinc chloride is a useful source of Zn²⁺ for the preparation of other zinc salts, for example zinc carbonate: Categories: Mineral stubs | Carbonate minerals ...

ZnCl₂(aq) + Na₂CO₃(aq) → ZnCO₃(s) + 2 NaCl(aq) Drinking water This article focuses on water as we experience it every day. ... Sodium carbonate (also known as washing soda or soda ash), Na2CO3, is a sodium salt of carbonic acid. ... Drinking water This article focuses on water as we experience it every day. ... Categories: Mineral stubs | Carbonate minerals ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the formula NaCl. ... Drinking water This article focuses on water as we experience it every day. ...

Preparation & purification

Anhydrous zinc chloride can be prepared from zinc and hydrogen chloride. General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ...

Zn + 2 HCl(g) → ZnCl₂(s) + H₂(g) General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... For other meanings see gas (disambiguation). ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... For other meanings see gas (disambiguation). ...

Hydrated forms and aqueous solutions may be readily prepared using standard acid-base methods, or from one of its ores, zinc sulfide: Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ...

ZnS(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂S(l) Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... Drinking water This article focuses on water as we experience it every day. ... Drinking water This article focuses on water as we experience it every day. ... Flash point -82. ... A liquid will assume the shape of its container. ...

Commercial samples of zinc chloride typically contain water and zinc oxychloride, the main hydrolysis product. Such samples may be purified as follows: 100 g of crude ZnCl₂ are heated to reflux in 800 mL anhydrous dioxan in the presence of zinc metal dust. The mixture is filtered while hot (to remove Zn), then allowed to cool to give pure ZnCl₂ as a white precipitate. Anhydrous samples can be purified by sublimation in a stream of hydrogen chloride gas, followed by heating up to 400°C in a stream of dry nitrogen gas. Water (from the Old English waeter; c. ... Hydrolysis is a chemical process in which a molecule is split into two parts by the addition of a molecule of water. ... 1,4-Dioxane, often just called dioxane, is a clear, colorless heterocyclic organic compound which is a liquid at room temperature and pressure. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... Sublimation of an element or substance is a conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...

Uses

One use for zinc chloride is as a flux for soldering. This is because of its ability (when molten) to dissolve metal oxides. This property also leads to its use in the manufacture of magnesia cements for dental fillings. ZnCl₂ has also been used as a fireproofing agent, for etching metals, and is also a primary ingredient in fabric refresheners such as Febreze. In metallurgy, flux is a substance which facilitates soldering, brazing, and welding by chemically cleaning the metals to be joined. ... (De)soldering a contact from a wire. ... Magnesium oxide is a white solid mineral that occurs naturally as periclase and is a source of magnesium. ... It has been suggested that this article or section be merged into dental restoration. ...

In the laboratory, zinc chloride finds wide use, principally as a moderate-strength Lewis acid. It can catalyse (A) the Fischer indole synthesis^[9], and also (B) Friedel-Crafts acylation reactions involving activated aromatic rings^[10]. In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ... Generic graph showing the effect of a catalyst in an hypotetical exothermic chemical reaction. ... The Fischer indole synthesis is a chemical reaction that produces the aromatic heterocycle indole from a (substituted) phenylhydrazine and an aldehyde or ketone under acidic conditions. ... The Friedel-Crafts reactions were developed by Charles Friedel and James Crafts in 1877. ... In chemistry, an aromatic molecule is one in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. ...

Download high resolution version (934x189, 10 KB)Some reactions of aromatic compounds involving ZnCl2 This image has been released into the public domain by its creator and original copyright holder. ...

Related to the latter is the classical preparation^[8] of the dye fluorescein from phthalic anhydride and resorcinol, which involves a Friedel-Crafts acylation. This has in fact been done successfully using the wet ZnCl₂ sample shown in the picture above. fluorescein isothiocyanate Fluorescein is a fluorophore commonly used in microscopy, in a type of dye laser as the gain medium, and in forensics and serology to detect latent blood stains. ... R-phrases , , , S-phrases , , , , , Flash point 152 °C RTECS number TI3150000 Supplementary data page Structure and properties n, εr, etc. ... Resorcin (or resorcinol) is the (1,3) isomer of dihydroxybenzene (dihydric phenol). ... The Friedel-Crafts reactions were developed by Charles Friedel and James Crafts in 1877. ...

Fluorescein preparation This image has been released into the public domain by its creator and original copyright holder. ...

Hydrochloric acid alone reacts poorly with primary alcohols and secondary alcohols, but a combination of HCl with ZnCl₂ (known together as the "Lucas reagent") at 130°C is effective for the preparation of alkyl chlorides. This probably reacts via an S_N2 mechanism with primary alcohols but via S_N1 with secondary alcohols. The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... The SN2 reaction is a type of nucleophilic substitution, where a nucleophile attacks an electrophilic center and bonds to it, expelling another group called a leaving group. ... The SN1 reaction is an substitution reaction in organic chemistry. ...

Alkyl chloride preparation catalysed by ZnCl2 This image has been released into the public domain by its creator and original copyright holder. ...

Zinc chloride is also able to activate benzylic and allylic halides towards substitution by weak nucleophiles such as alkenes^[11]: An allyl group is an alkene hydrocarbon group with the formula H2C=CH-CH2-. It is made up of a vinyl group, CH2=CH-, attached to a methylene -CH2. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... An alkene in organic chemistry is an unsaturated hydrocarbon containing at least one carbon to carbon double bond. ...

Benzylation of an alkene catalysed by ZnCl2 This image has been released into the public domain by its creator and original copyright holder. ...

In similar fashion, ZnCl₂ promotes selective NaBH₃CN reduction of tertiary, allylic or benzylic halides to the corresponding hydrocarbons. Sodium cyanoborohydride (NaBH3(CN) is a chemical compound. ...

Zinc chloride is also a useful starting point for the synthesis of many organozinc reagents, such as those used in the palladium catalysed Negishi coupling with aryl halides or vinyl halides^[12]. In such cases the organozinc compound is usually prepared by transmetallation from an organolithium or a Grignard reagent, for example: In organic chemistry, a halogenoarene, haloarene, or aryl halide, is an organic compound in which a halogen atom is bonded to a carbon atom which is part of an aromatic ring. ... A vinyl halide in chemistry is any alkene with at least one halide substituent. ... An organolithium reagent is an organometallic compound with a direct bond between a carbon and a lithium atom. ... A Grignard Reagent is an alkyl- or aryl- magnesium halide. ...

Download high resolution version (811x216, 18 KB)Example of a Negishi reaction using ZnCl2 This image has been released into the public domain by its creator and original copyright holder. ...

Zinc enolates, prepared from alkali metal enolates and ZnCl₂, provide control of stereochemistry in aldol condensation reactions due to chelation on to the zinc. In the example shown below, the threo product was favored over the erythro by a factor of 5:1 when ZnCl₂ in DME/ether was used^[13]. This is because the chelate is more stable when the bulky phenyl group is pseudo-equatorial rather than pseudo-axial, i.e., threo rather than erythro. Enol (or, more officially, but less commonly: alkenol) is an alkene with hydroxyl group on one of the carbon atoms of the double bond. ... The different types of isomers. ... An aldol reaction takes the following form: 2 enolate anions ↔ aldol The reaction requires a base catalyst. ... Chelation (from Greek χηλή, chelè, meaning claw) is the process of reversible binding of a ligand, the chelant, chelator or chelating agent, to a metal ion, forming a metal complex, the chelate. ... Diastereomers are stereoisomers that are not enantiomers or mirror images of each other. ... Diastereomers are stereoisomers that are not enantiomers or mirror images of each other. ... Flash point -45 °C Autoignition temperature 170 °C R/S statement RTECS number KI5775000 Supplementary data page Structure and properties n, εr, etc. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Axial has different meanings: In geometry it means: along the same line as an axis (coaxial) or centerline: parallel (geometry), contrary to radial or perpendicular In anatomy it relates to an anatomical direction of animals and humans. ...

Download high resolution version (944x269, 31 KB)Stereochemistry of ZnCl2 assisted aldol reactions This image has been released into the public domain by its creator and original copyright holder. ...

Precautions

Corrosive, irritant. Wear gloves and goggles.

Suppliers/Manufacturers

• Advance Scientific & Chemical.
• Alfa Aesar.
• Sigma-Aldrich.
• Strem Chemicals.
• Fisher.
• VWR.

References

1. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
2. Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
3. The Merck Index, 7th edition, Merck & Co, Rahway, New Jersey, USA, 1960.
4. D. Nicholls, Complexes and First-Row Transition Elements, Macmillan Press, London, 1973.
5. A. F. Wells, 'Structural Inorganic Chemistry, 5th ed., Oxford University Press, Oxford, UK, 1984.
6. J. March, Advanced Organic Chemistry, 4th ed., p. 723, Wiley, New York, 1992.
7. G. J. McGarvey, in Handbook of Reagents for Organic Synthesis, Volume 1: Reagents, Auxiliaries and Catalysts for C-C Bond Formation, (R. M. Coates, S. E. Denmark, eds.), pp. 220-3, Wiley, New York, 1999.
8. B. S. Furnell et al., Vogel's Textbook of Practical Organic Chemistry, 5th edition, Longman/Wiley, New York, 1989.
9. R. L. Shriner, W. C. Ashley, E. Welch, in Organic Syntheses Collective Volume 3, p 725, Wiley, New York, 1955.
10. (a) S. R. Cooper, in Organic Syntheses Collective Volume 3, p 761, Wiley, New York, 1955. (b) S. Y. Dike, J. R. Merchant, N. Y. Sapre, Tetrahedron, 47, 4775 (1991).
11. E. Bauml, K. Tschemschlok, R. Pock, H. Mayr, Tetrahedron Letters, 29, 6925 (1988).
12. S. Kim, Y. J. Kim, K. H. Ahn, Tetrahedron Letters, 24, 3369 (1983).
13. H. O. House, D. S. Crumrine, A. Y. Teranishi, H. D. Olmstead, Journal of the American Chemical Society, 95, 3310 (1973).

External links

• PubChem ZnCl₂ summary.
• External MSDS Data Sheet.