Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Silver chloride: Difference between pages

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{{short description|Chemical compound with the formula AgCl}}

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| verifiedrevid = 464390969

| Name =

| ImageFile = Chlorid stříbrný.PNG

| ImageFile1 = Silver-chloride-3D-ionic.png

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| IUPACName = Silver(I) chloride

| OtherNames = Cerargyrite<br />[[Chlorargyrite]]<br />Horn silver <br/> Argentous chloride

| SystematicName =

| Section1 = {{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| PubChem = 24561

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| Section2 = {{Chembox Properties

| Appearance = White solid

| MeltingPt_notes =

| BoilingPt_notes =

| SolubleOther =

soluble in [[ammonia|NH₃]], conc. [[hydrochloric acid|HCl]], conc. [[sulfuric acid|H₂SO₄]], alkali [[cyanide]], [[ammonium carbonate|(NH₄)₂CO₃]], [[potassium bromide|KBr]], [[sodium thiosulfate|Na₂S₂O₃]];<br />

insoluble in [[ethanol|alcohol]], dilute [[acid]]s.

| SolubilityProduct = 1.77{{e|&minus;10}}<ref name="crc">{{cite book |author1=John Rumble |title=CRC Handbook of Chemistry and Physics |date=June 18, 2018 |publisher=CRC Press |isbn=978-1138561632 |pages=5–189|edition=99 |language=English}}</ref>

| pKb =

| MagSus = &minus;49.0·10⁻⁶ cm³/mol

}}

| Section3 = {{Chembox Structure

| Structure_ref = <ref name="cryst">{{cite journal |author1=S. Hull |author2=D. A. Keen |title=Pressure-induced phase transitions in AgCl, AgBr, and AgI |journal=Physical Review B |date=1999 |volume=59 |issue=2 |pages=750–761 |doi=10.1103/PhysRevB.59.750 |publisher=APS |bibcode=1999PhRvB..59..750H |s2cid=123044752 |language=en}}</ref>

| CrystalStruct = [[Cubic crystal system|cubic]]

| SpaceGroup = Fm{{overline|3}}m (No. 225)

| Coordination = Octahedral

| MolShape =

| LattConst_a = 555 [[picometer|pm]]

}}

| Section4 = {{Chembox Thermochemistry

| DeltaHf = −127&nbsp;kJ·mol⁻¹<ref name=b1>{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| publisher = Houghton Mifflin Company| year = 2009| isbn = 978-0-618-94690-7|page=A23}}</ref>

| Entropy = 96&nbsp;J·mol⁻¹·K⁻¹<ref name=b1/>

}}

| Section5 = {{Chembox Pharmacology

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| Section6 = {{Chembox Explosive

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| Section7 = {{Chembox Hazards

| ExternalSDS = [https://fscimage.fishersci.com/msds/20787.htm Fischer Scientific], [http://www.saltlakemetals.com/MSDS_Silver_Chloride.htm Salt Lake Metals]

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| Section8 = {{Chembox Related

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}}

'''Silver chloride''' is an [[inorganic chemical compound]] with the [[chemical formula]] [[Silver|Ag]][[Chlorine|Cl]]. This white [[crystal]]line solid is well known for its low [[solubility]] in [[water]] and its [[Photosensitivity|sensitivity to light]]. Upon illumination or heating, silver chloride converts to silver (and chlorine), which is signaled by grey to black or purplish coloration in some samples. AgCl occurs naturally as the mineral [[chlorargyrite]].

It is produced by a [[salt metathesis reaction|metathesis reaction]] for use in [[photography]] and in [[pH meter]]s as [[silver chloride electrode|electrodes]].

==Preparation==

Silver chloride is unusual in that, unlike most [[chloride]] salts, it has very low solubility. It is easily synthesized by [[Salt metathesis reaction|metathesis]]: combining an [[aqueous solution]] of [[silver nitrate]] (which is soluble) with a soluble chloride salt, such as [[sodium chloride]] (which is used industrially as a method of producing AgCl), or [[cobalt(II) chloride]]. The silver chloride that forms will precipitate immediately.<ref name="b1" /><ref name="ullmann" />{{Rp|at=46}}

:<chem>AgNO3 + NaCl -> AgCl(v) + NaNO3</chem>

:<chem>2 AgNO3 + CoCl2 -> 2 AgCl(v) + Co(NO3)2</chem>

It can also be produced by the reaction of silver metal and [[aqua regia]]; however, the insolubility of silver chloride decelerates the reaction. Silver chloride is also a [[by-product]] of the [[Miller process]], where silver metal is reacted with chlorine gas at elevated temperatures.<ref name="ullmann">{{cite encyclopedia |last=Brumby|first=Andreas|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|title=Silver, Silver Compounds, and Silver Alloys|date=2008 |doi=10.1002/14356007.a24_107.pub2|isbn=9783527303854 }}</ref>{{Rp|at=21}}<ref name="greenwood">{{cite book |author1=N. N. Greenwood |author2=A. Earnshaw |title=Chemistry of the Elements |date=1997 |publisher=[[Butterworth-Heinemann]] |location=Oxford, UK |isbn=9780750633659 |pages=1173–1200 |edition=2 |language=en}}</ref>

==History==

Silver chloride has been known since ancient times. [[Ancient Egyptians]] produced it as a method of refining silver, which was done by roasting silver ores with salt to produce silver chloride, which was subsequently decomposed to silver and chlorine.<ref name="ullmann" />{{Rp|at=19}} However, it was later identified as a distinct compound of silver in 1565 by [[Georg Fabricius]].<ref name="pot">Potonniée, Georges (1973). ''The history of the discovery of photography''. Arno Press. p. 50. {{ISBN|0-405-04929-3}}</ref><ref name="hannavy">{{cite book |editor1-last=Hannavy |editor1-first=John |title=Encyclopedia of Nineteenth-Century Photography |date=2008 |publisher=Taylor & Francis |isbn=9781135873271 |page=857}}</ref> Silver chloride, historically known as ''luna cornea'' (which could be translated as "horn silver" as the moon [[Classical planet#Alchemy|was an alchemic codename]] for silver),<ref name="hannavy" /> has also been an intermediate in other historical silver refining processes. One such example is the [[Augustin process]] developed in 1843, wherein copper ore containing small amounts of silver is roasted in chloridizing conditions and the silver chloride produced is leached by [[brine]], where it is more soluble.<ref name="ullmann" />{{Rp|at=32}}

Silver-based photographic films were first made in 1727 by [[Johann Heinrich Schulze]] with [[silver nitrate]]. However, he was not successful in making permanent images, as they faded away.<ref name="Watt2003">{{cite book |author=Susan Watt |url=https://books.google.com/books?id=TYPyWkuRJqYC&pg=PA21 |title=Silver |publisher=Marshall Cavendish |year=2003 |isbn=978-0-7614-1464-3 |pages=21– |quote=... But the first person to use this property to produce a photographic image was German physicist Johann Heinrich Schulze. In 1727, Schulze made a paste of silver nitrate and chalk, placed the mixture in a glass bottle, and wrapped the bottle in ... |accessdate=28 July 2013}}</ref> Later in 1816, the use of silver chloride was introduced into photography by [[Nicéphore Niépce]].<ref name="ullmann" />{{Rp|at=38–39}}<ref>[https://photo-museum.org/niepce-invention-photography/ Niépce House Museum: Invention of Photography: 1816-1818, Niépce's first tries] (retrieved 2024-02-23)</ref>

==Structure==

[[Image:AgCl pyramidal.jpg|thumb|left|Pyramidal crystals of AgCl]]

The solid adopts the [[Face-centered cubic|''fcc'']] [[Sodium chloride|NaCl]] structure, in which each Ag⁺ ion is surrounded by an [[octahedron]] of six chloride ligands. [[Silver(I) fluoride|AgF]] and [[Silver bromide|AgBr]] crystallize similarly.<ref>Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. {{ISBN|0-19-855370-6}}. p. 349</ref> However, the crystallography depends on the condition of crystallization, primarily free silver ion concentration, as is shown in the picture to the left (greyish tint and metallic [[lustre (mineralogy)|lustre]] are due to partially [[redox|reduce]]d [[silver]]).<ref>{{cite journal |author1=Boris A. Sechkarev |title=Mass crystallization of silver chloride microcrystals |journal=Microscopy Research and Technique |date=1998 |volume=42 |issue=2 |pages=145–147 |doi=10.1002/(SICI)1097-0029(19980715)42:2<145::AID-JEMT8>3.0.CO;2-S |pmid=9728885 |s2cid=45866801 |language=en}}</ref>

Above 7.5 [[gigapascal|GPa]], silver chloride transitions into a [[Monoclinic crystal system|monoclinic]] KOH phase. Then at 11 GPa, it undergoes another phase change to an [[orthorhombic crystal system|orthorhombic]] [[thallium(I) iodide|TlI]] phase.<ref name="cryst" />

==Reactions==

AgCl dissolves in solutions containing [[ligand]]s such as [[chloride]], [[cyanide]], [[triphenylphosphine]], [[thiosulfate]], [[thiocyanate]] and [[ammonia]]. Silver chloride reacts with these ligands according to the following illustrative equations:<ref name="ullmann" />{{Rp|at=25–33}}

:<chem>AgCl (s) + 2 CN^- (aq) -> Ag(CN)2^- (aq) + Cl^- (aq)</chem>

:<chem>AgCl (s) + 2 S2O3^2- (aq) ->(Ag(S2O3)2)^3- (aq) + Cl^- (aq)</chem>

:<chem>AgCl (s) + 2 NH3(aq) -> Ag(NH3)2+ (aq) + Cl^- (aq)</chem>

Of these reactions used to leach silver chloride from silver ores, cyanidation is the most commonly used. Cyanidation produces the soluble [[potassium dicyanoargentate|dicyanoargentate]] complex, which is later turned back to silver by reduction.<ref name="ullmann" />{{Rp|at=26}}

Silver chloride does not react with nitric acid, but instead reacts with sulfuric acid to produce [[silver sulfate]].<ref name="Kirk">{{Cite book|title=Kirk-Othmer Encyclopedia of Chemical Technology|last=Etris|first=Samuel|year=2003|isbn=9780471484943|chapter=Silver Compounds

|doi=10.1002/0471238961.1909122203011616.a01.pub2}}</ref> Then the sulfate is protonated in the presence of sulfuric acid to [[bisulfate]], which can be reversed by dilution. This reaction is used to separate silver from other platinum group metals.<ref name="ullmann" />{{Rp|at=42}}

Most complexes derived from AgCl are two-, three-, and, in rare cases, four-coordinate, adopting linear, trigonal planar, and tetrahedral coordination geometries, respectively.<ref name="arsenic" />

:<chem>3AgCl(s) + Na3AsO3(aq) -> Ag3AsO3(s) + 3NaCl(aq)</chem>

:<chem>3AgCl(s) +Na3AsO4(aq) -> Ag3AsO4(s) + 3NaCl(aq)</chem>

These two reactions are particularly important in the [[Qualitative inorganic analysis|qualitative analysis]] of AgCl in labs as AgCl is white, which changes to <chem>Ag3AsO3</chem> (silver arsenite) which is yellow, or <chem>Ag3AsO4</chem>([[silver arsenate]]) which is reddish brown.<ref name="arsenic">{{cite book |last=Godfrey |first=S.M.|editor-first=N.C. |editor-last=Norman |title=Chemistry of Arsenic, Antimony and Bismuth |publisher=Blackie Academic and Professional |date=1998 |chapter=Chapter 3|isbn=0-7514-0389-X|display-authors=etal}}</ref>

==Chemistry==

[[File:Decomposition of Silver Chloride.jpg|thumb|right|Silver chloride decomposes over time with exposure to UV light]]

In one of the most famous reactions in chemistry, the addition of colorless aqueous [[silver nitrate]] to an equally colorless solution of sodium chloride produces an opaque white precipitate of AgCl:<ref>{{Cite web|url=http://www.epa.gov/sw-846/pdfs/9076.pdf |title=TEST METHOD FOR TOTAL CHLORINE IN NEW AND USED PETROLEUM PRODUCTS BY OXIDATIVE COMBUSTION AND MICROCOULOMETRY |archive-url=https://web.archive.org/web/20071203133343/http://www.epa.gov/sw-846/pdfs/9076.pdf |archive-date=December 3, 2007 |date=September 1994 |website=Environmental Protection Agency}}</ref>

:<chem>Ag+ (aq) + Cl^- (aq) -> AgCl (s)</chem>

This conversion is a common test for the presence of [[chloride]] in solution. Due to its conspicuousness, it is easily used in titration, which gives the typical case of [[argentometry]].<ref name="Kirk" />

The [[solubility product]], ''K''_sp, for AgCl in water is {{val|1.77e-10}} at room temperature, which indicates that only 1.9&nbsp;mg (that is, <math>\sqrt{1.77\times 10^{-10}} \ \mathrm{mol}</math>) of AgCl will dissolve per liter of water.<ref name="crc" /> The chloride content of an aqueous solution can be determined quantitatively by weighing the precipitated AgCl, which conveniently is non-hygroscopic since AgCl is one of the few transition metal chlorides that are insoluble in water.

Interfering ions for this test are bromide and iodide, as well as a variety of ligands (see [[silver halide]]).

For AgBr and AgI, the ''K''_sp values are 5.2 x 10⁻¹³ and 8.3 x 10⁻¹⁷, respectively. [[Silver bromide]] (slightly yellowish white) and [[silver iodide]] (bright yellow) are also significantly more photosensitive than is AgCl.<ref name="crc" /><ref name="ullmann" />{{Rp|at=46}}

AgCl quickly darkens on exposure to light by disintegrating into elemental [[chlorine]] and metallic [[silver]]. This reaction is used in photography and film and is the following:<ref name="greenwood" />

:Cl⁻ + ''hν'' → Cl + e⁻ (excitation of the chloride ion, which gives up its extra electron into the conduction band)

:Ag⁺ + e⁻ → Ag (liberation of a silver ion, which gains an electron to become a silver atom)

The process is not reversible because the silver atom liberated is typically found at a [[crystal defect]] or an impurity site so that the electron's energy is lowered enough that it is "trapped".<ref name="greenwood" />

==Uses==

===Silver chloride electrode===

Silver chloride is a constituent of the [[silver chloride electrode]] which is a common reference electrode in [[electrochemistry]]. The electrode functions as a reversible [[redox electrode]] and the equilibrium is between the solid [[silver]] metal and silver chloride in a chloride solution of a given concentration. It is usually the internal reference electrode in [[pH meter]]s and it is often used as a reference in [[reduction potential]] measurements. As an example of the latter, the silver chloride electrode is the most commonly used reference electrode for testing [[cathodic protection]] [[corrosion]] control systems in [[seawater]] environments.<ref>Bates, R.G. and MacAskill, J.B. (1978). "Standard potential of the silver-silver chloride electrode". ''Pure & Applied Chemistry'', Vol. 50, pp. 1701–1706, http://www.iupac.org/publications/pac/1978/pdf/5011x1701.pdf</ref>

===Photography===

Silver chloride and silver nitrate have been used in [[photography]] since it began, and are well known for their light sensitivity.<ref name="pot" /> It was also a vital part of the [[Daguerreotype]] sensitization where silver plates were fumed with chlorine to produce a thin layer of silver chloride.<ref>{{cite web |title=The Daguerreotype Process |url=https://www.photohistory-sussex.co.uk/dagprocess.htm |website=Sussex PhotoHistory |access-date=19 June 2023}}</ref> Another famous process that used silver chloride was the [[gelatin silver process]] where embedded silver chloride crystals in [[gelatin]] were used to produce images.<ref>{{cite web |title=SILVER GELATIN |url=https://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/atlas_silver_gelatin.pdf |website=Getty.edu |publisher=Getty |access-date=19 June 2023}}</ref> However, with advances in [[color photography]], these methods of black-and-white photography have dwindled. Even though color photography uses silver chloride, it only works as a mediator for transforming light into organic image dyes.<ref name="photo">{{cite book |author1=P. Bergthaller |title=Chemistry and Technology of Printing and Imaging Systems |date=1996 |pages=35–75 |publisher=Springer, Dordrecht |isbn=9789401042659 |url=https://doi.org/10.1007/978-94-011-0601-6_3 |language=en |chapter=Silver halide photography|doi=10.1007/978-94-011-0601-6_3 }}</ref>

Other photographic uses include making [[photographic paper]], since it reacts with photons to form [[latent image|latent images]] via photoreduction; and in [[photochromic lens]]es, taking advantage of its reversible conversion to Ag metal. Unlike photography, where the photoreduction is irreversible, the glass prevents the electron from being 'trapped'.<ref>{{cite book |author1=R.J. Araujo |title=Encyclopedia of Physical Science and Technology |date=2003 |publisher=Academic Press |isbn=9780122274107 |edition=Third |url=https://doi.org/10.1016/B0-12-227410-5/00567-6 |access-date=20 June 2023 |chapter=Photochromic Glasses|pages=49–56 |doi=10.1016/B0-12-227410-5/00567-6 }}</ref> These photochromic lenses are used primarily in [[sunglasses]].<ref name="ullmann" />

===Antimicrobial agent===

Silver chloride nanoparticles are widely sold commercially as an [[antimicrobial]] agent.<ref name="Kirk" /><ref>{{cite web |title=CVS Health Anti-Microbial Silver Wound Gel |url=https://www.cvs.com/shop/cvs-health-anti-microbial-silver-wound-gel-prodid-445926 |website=CVS |access-date=25 February 2024}}</ref> The antimicrobial activity of silver chloride depends on the particle size, but are usually below 100 [[nanometer|nm]]. In general, silver chloride is antimicrobial against various [[bacteria]], such as [[E. coli]].<ref name="antimicro">{{cite journal |author1=Nelson Durán |author2=Gerson Nakazato |author3=Amedea B. Seabra |title=Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments |journal=Applied Microbiology and Biotechnology |date=2016 |volume=100 |issue=15 |pages=6555–6570 |doi=10.1007/s00253-016-7657-7 |pmid=27289481 |s2cid=253765691 |language=en}}</ref>

Silver chloride nanoparticles for use as a microbial agent can be produced by a metathesis reaction between aqueous silver and chloride ions or can be [[biogenic substance|biogenically]] synthesized by [[fungi]] and [[plants]].<ref name="antimicro" /><ref>{{cite journal |author1=Yun Ok Kang |author2=Ju-Young Jung |author3=Donghwan Cho |author4=Oh Hyeong Kwon |author5=Ja Young Cheon |author6=Won Ho Park |title=Antimicrobial Silver Chloride Nanoparticles Stabilized with Chitosan Oligomer for the Healing of Burns |journal=Materials |date=2016 |volume=9 |issue=4 |page=215 |doi=10.3390/ma9040215 |doi-access=free |pmid=28773340 |pmc=5502666 |bibcode=2016Mate....9..215K |language=en}}</ref>

===Other uses===

Silver chloride's low solubility makes it a useful addition to pottery glazes for the production of "Inglaze [[lustre (mineralogy)|lustre]]".

Silver chloride has been used as an antidote for [[mercury poisoning]], assisting in the elimination of [[mercury (element)|mercury]].

Other uses of AgCl include:<ref name="ullmann" />

* in [[bandage]]s and wound healing products,<ref name="ullmann" />{{Rp|at=83}}

* to create yellow, amber, and brown shades in [[stained glass]] manufacture,<ref>{{cite journal |author1=John Lowe |title=The Conservation of Stained Glass |journal=Studies in Conservation |date=1975 |volume=2- |issue=1 |pages=93–97 |doi=10.1179/sic.1975.s1.016 |language=en}}</ref> and

* as an [[infrared]] transmissive optical component, as it can be hot-pressed into window and lens shapes.<ref>{{Cite web|url=https://www.crystran.co.uk/optical-materials/silver-chloride-agcl|title=Silver Chloride (AgCl) Optical Material|website=www.crystran.co.uk|url-status=live|archive-url=https://web.archive.org/web/20120905014123/http://www.crystran.co.uk/silver-chloride-agcl.htm|archive-date=September 5, 2012|access-date=2019-12-04}}</ref>

==Natural occurrence==

[[File:Chlorargyrite-Embolite-rh3-10a.jpg|thumb|Chlorargyrite]]

Silver chloride occurs naturally as [[chlorargyrite]] in the arid and oxidized zones in silver deposits. If some of the chloride ions are replaced by bromide or iodide ions, the words bromian and iodian are added before the name, respectively.<ref>{{cite web |title=Chlorargyrite |url=https://www.mindat.org/min-1014.html |website=mindat.org |access-date=7 June 2023}}</ref> This mineral is a source of silver and is leached by cyanidation, where it will produce the soluble [Ag(CN)₂]^– complex.<ref name="ullmann" />{{Rp|at=26}}

== Safety ==

According to the [[European Chemicals Agency|ECHA]], silver chloride may damage the [[Prenatal development|unborn child]], is very toxic to aquatic life with long lasting effects and may be [[Corrosion|corrosive]] to metals.<ref>{{Cite web |title=Brief Profile - ECHA |url=https://echa.europa.eu/brief-profile/-/briefprofile/100.029.121 |access-date=2024-03-27 |website=echa.europa.eu |language=en-GB}}</ref>

==See also==

* [[Photosensitive glass]]

==References==

{{Reflist}}

{{Silver compounds}}

{{Chlorides}}

{{Authority control}}

{{DEFAULTSORT:Silver Chloride}}

[[Category:Chlorides]]

[[Category:Silver compounds]]

[[Category:Metal halides]]

[[Category:Coordination complexes]]

[[Category:Photographic chemicals]]

[[Category:Light-sensitive chemicals]]

[[Category:Rock salt crystal structure]]