wiki143 - User contributions [en]

Silver nitrate

2025-09-30T14:27:12Z

150.128.167.154: /* Reactions */ added nbsp

{{chembox
|Watchedfields = changed
|verifiedrevid = 476997183
|Name = Silver nitrate
|ImageFile1 = Silver-nitrate-2D.svg
|ImageClass1 = skin-invert
|ImageSize1 = 160px
|ImageName1 = Structural formula of silver nitrate
|ImageCaption1 = [[Structural formula]]
|ImageFile2 = Silver nitrate crystals.jpg
|ImageSize2 = 160px
|ImageName2 = Sample of silver nitrate
|ImageFile3 = Silver-nitrate-xtal-2x2x2-c-3D-bs-17.png
|ImageName3 = Crystal structure of silver nitrate
|ImageCaption3 = [[Crystal structure]]
|IUPACName = Silver nitrate
|OtherNames = Nitric acid silver(1+) salt Lapis infernalis Argentous nitrate
|SystematicName = Silver(I) nitrate
|Section1 = {{Chembox Identifiers
|ChemSpiderID = 22878
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChEMBL = 177367
|ChEMBL_Ref = {{ebicite|correct|EBI}}
|PubChem = 24470
|UNII = 95IT3W8JZE
|UNII_Ref = {{fdacite|correct|FDA}}
|InChI = 1/Ag.NO3/c;2-1(3)4/q+1;-1
|InChIKey = SQGYOTSLMSWVJD-UHFFFAOYAW
|SMILES = [N+](=O)([O-])[O-].[Ag+]
|StdInChI = 1S/Ag.NO3/c;2-1(3)4/q+1;-1
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = SQGYOTSLMSWVJD-UHFFFAOYSA-N
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|CASNo = 7761-88-8
|CASNo_Ref = {{cascite|correct|CAS}}
|ChEBI = 32130
|ChEBI_Ref = {{ebicite|correct|EBI}}
|RTECS = VW4725000
|UNNumber = 1493
|EC_number = 231-853-9
}}
|Section2 = {{Chembox Properties
|Ag=1 | N=1 | O=3
|Appearance = colorless crystalline solid
|Odor = Odorless
|Density = 4.35 g/cm3 (24 °C) 3.97 g/cm3 (210 °C)<ref name=crc>{{CRC90}}</ref>
|MeltingPtC = 209.7
|MeltingPt_ref = <ref name=crc /><ref name=chemister />
|BoilingPtC = 440
|BoilingPt_notes = decomposes<ref name=crc />
|Solubility = 122 g/100 mL (0 °C) 170 g/100 mL (10 °C) 256 g/100 mL (25 °C) 373 g/100 mL (40 °C) 912 g/100 mL (100 °C)<ref name=sioc>{{cite book|last1 = Seidell|first1 = Atherton|last2 = Linke|first2 = William F.|year = 1919|title = Solubilities of Inorganic and Organic Compounds|url = https://archive.org/details/solubilitiesino04seidgoog|publisher = D. Van Nostrand Company|place = [[New York City]]|edition = 2nd|pages = [https://archive.org/details/solubilitiesino04seidgoog/page/n642 617]–619}}</ref>
|SolubleOther = Soluble in [[acetone]],<ref name=crc /> [[ammonia]], [[diethyl ether|ether]], [[glycerol]]
|Solubility1 = 0.776 g/kg (30 °C) 1.244 g/kg (40 °C) 5.503 g/kg (93 °C)<ref name=chemister>{{cite web|last = Kiper |first = Ruslan Anatolievich|website = Chemister.ru |url = http://chemister.ru/Database/properties-en.php?dbid=1&id=862|title = silver nitrate|access-date = 2014-07-20}}</ref>
|Solvent1 = acetic acid
|Solubility2 = 0.35 g/100 g (14 °C) 0.44 g/100 g (18 °C)<ref name=sioc />
|Solvent2 = acetone
|Solubility3 = 0.22 g/kg (35 °C) 0.44 g/kg (40.5 °C)<ref name=sioc />
|Solvent3 = benzene
|Solubility4 = 3.1 g/100 g (19 °C)<ref name=sioc />
|Solvent4 = ethanol
|Solubility5 = 2.7 g/100 g (20 °C)<ref name=chemister />
|Solvent5 = ethyl acetate
|RefractIndex = 1.744
|Viscosity = 3.77 [[Poise (unit)|cP]] (244 °C) 3.04 cP (275 °C)<ref name=chemister />
|LogP = 0.19
|MagSus = −45.7·10−6 cm3/mol
}}
|Section3 = {{Chembox Structure
|CrystalStruct = Orthorhombic, [[pearson symbol|oP56]]<ref name=iucr />
|SpaceGroup = P212121, No. 19<ref name=iucr />
|PointGroup = 222<ref name=iucr />
|LattConst_a = 6.992(2) Å
|LattConst_b = 7.335(2) Å
|LattConst_c = 10.125(2) Å<ref name=iucr />
|LattConst_alpha = 90
}}
|Section4 = {{Chembox Thermochemistry
|DeltaHf = −124.4 kJ/mol<ref name=crc />
|DeltaGf = −33.4 kJ/mol<ref name=crc />
|Entropy = 140.9 J/mol·K<ref name=crc />
|HeatCapacity = 93.1 J/mol·K<ref name=crc />
}}
|Section5 = {{Chembox Pharmacology
|ATCCode_prefix = D08
|ATCCode_suffix = AL01
}}
|Section6 = {{Chembox Hazards
|GHSPictograms = {{GHS03}}{{GHS05}}{{GHS06}}{{GHS09}}<ref name="sigma">{{Sigma-Aldrich|id = 204390|name = Silver nitrate|accessdate = 2014-07-20}}</ref>
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|272|314|410}}<ref name="sigma" />
|PPhrases = {{P-phrases|220|273|280|305+351+338|310|501}}<ref name="sigma" />
|NFPA-H = 3
|NFPA-F = 0
|NFPA-R = 2
|NFPA-S = OX
|MainHazards = Reacts explosively with ethanol. Toxic. Corrosive.
|LDLo = 800 mg/kg (rabbit, oral) 20 mg/kg (dog, oral)<ref>{{IDLH|7440224|Silver (metal dust and soluble compounds, as Ag)}}</ref>
}}
}}
[[File:AgNO3 microscope 2.JPG|thumb|Crystals of silver nitrate under a microscope.]]

'''Silver nitrate''' is an [[inorganic compound]] with [[chemical formula]] {{chem|AgNO|3}}. It is a versatile [[Precursor (chemistry)|precursor]] to many other [[silver]] compounds, such as those used in [[photography]]. It is far less sensitive to light than the [[silver halide|halides]].{{Citation needed|date=July 2024}} It was once called ''lunar caustic'' because silver was called ''luna'' by ancient alchemists who associated silver with the [[moon]].<ref>{{cite web|url=http://dictionary.die.net/lunar%20caustic|title=Definition of Lunar Caustic|work=dictionary.die.net|url-status=dead|archive-url=https://web.archive.org/web/20120131215637/http://dictionary.die.net/lunar%20caustic|archive-date=2012-01-31}}</ref> In solid silver [[nitrate]], the silver ions are three-[[Coordination complex|coordinated]] in a trigonal planar arrangement.<ref name=iucr>{{cite journal | title = Structure du nitrate d'argent à pression et température ordinaires. Exemple de cristal parfait | first1 = P. | last1 = Meyer | first2 = A. | last2 = Rimsky | first3 = R. | last3 = Chevalier | journal = [[Acta Crystallographica B|Acta Crystallogr. B]] | year = 1978 | volume = 34 | issue = 5 | pages = 1457–1462 | doi = 10.1107/S0567740878005907 | bibcode = 1978AcCrB..34.1457M }}</ref>

==Synthesis and structure==
[[Albertus Magnus]], in the 13th century, documented the ability of [[nitric acid]] to separate [[gold]] and [[silver]] by dissolving the silver.<ref>{{cite book|last = Szabadváry|first = Ferenc|title = History of analytical chemistry|publisher = Taylor & Francis|year = 1992|page = 17|url = https://books.google.com/books?id=53APqy0KDaQC&pg=PA17|isbn = 978-2-88124-569-5}}</ref> Indeed silver nitrate can be prepared by dissolving silver in [[nitric acid]] followed by evaporation of the solution. The stoichiometry of the reaction depends upon the concentration of nitric acid used.
:3 Ag + 4 HNO3 (cold and diluted) → 3 AgNO3 + 2 H2O + [[nitric oxide|NO]]
:Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + [[nitrogen dioxide|NO2]]

The structure of silver nitrate has been examined by [[X-ray crystallography]] several times. In the common orthorhombic form stable at ordinary temperature and pressure, the silver atoms form pairs with Ag---Ag contacts of 3.227 Å. Each Ag+ center is bonded to six oxygen centers of both uni- and bidentate nitrate ligands. The Ag-O distances range from 2.384 to 2.702 Å.<ref name=iucr />

[[File:Silver-nitrate-xtal-Ag-coordination-3D-bs-17.png|200px|Silver coordination environment in the crystal structure of silver nitrate]]

==Reactions==
A typical reaction with silver nitrate is to suspend a rod of [[copper]] in a solution of silver nitrate and leave it for a few hours. The silver nitrate reacts with copper to form hairlike crystals of silver metal and a blue solution of [[copper nitrate]]:
: 2 AgNO3 + Cu → Cu(NO3)2 + 2 Ag

Silver nitrate decomposes when heated:
: 2 AgNO3(l) → 2 [[Silver|Ag]](s) + [[oxygen|O2]](g) + 2 [[Nitrogen dioxide|NO2]](g)

Qualitatively, decomposition is negligible below the melting point, but becomes appreciable around 250 °C and fully decomposes at 440 °C.<ref>{{Cite journal | doi = 10.1063/1.3253104| title = High Temperature Properties and Decomposition of Inorganic Salts Part 3, Nitrates and Nitrites| journal = Journal of Physical and Chemical Reference Data| volume = 1| issue = 3| pages = 747–772| year = 1972| last1 = Stern | first1 = K. H. | bibcode = 1972JPCRD...1..747S| s2cid = 95532988}}</ref>

Most metal nitrates thermally decompose to the respective [[oxide]]s, but [[silver oxide]] decomposes at a lower temperature than silver nitrate, so the decomposition of silver nitrate yields elemental silver instead.

==Uses==

===Precursor to other silver compounds===
Silver nitrate is the least expensive [[Salt (chemistry)|salt]] of silver; it offers several other advantages as well. It is non-[[hygroscopic]], in contrast to [[silver fluoroborate]] and [[silver perchlorate]]. In addition, it is relatively stable to light, and it dissolves in numerous solvents, including water. The nitrate can be easily replaced by other [[ligands]], rendering AgNO3 versatile. Treatment with solutions of halide ions gives a precipitate of AgX (X = Cl, Br, I). When making [[photographic film]], silver nitrate is treated with [[halide]] salts of sodium or potassium to form insoluble [[silver halide]] in situ in photographic [[gelatin]], which is then applied to strips of tri-[[acetate]] or [[polyester]]. Similarly, silver nitrate is used to prepare some silver-based explosives, such as the [[silver fulminate|fulminate]], [[silver azide|azide]], or [[silver acetylide|acetylide]], through a [[precipitation reaction]].

Treatment of silver nitrate with base gives dark grey [[silver oxide]]:<ref>{{OrgSynth|author = Campaigne, E.; LeSuer, W. M.|title = 3-Thiophenecarboxylic (Thenoic) Acid|collvol = 4|collvolpages = 919|year = 1963|prep = cv4p0919}} (preparation of Ag2O, used in oxidation of an aldehyde)</ref>
:2 AgNO3 + 2 NaOH → Ag2O + 2 NaNO3 + H2O

===Halide abstraction===
The silver cation, {{chem|Ag|+}}, reacts quickly with halide sources to produce the insoluble silver halide, which is a cream precipitate if {{chem|Br|-}} is used, a white precipitate if {{chem|Cl|-}} is used and a yellow precipitate if {{chem|I|-}} is used. This reaction is commonly used in [[inorganic chemistry]] to abstract halides:

:{{chem|Ag|+}}(aq) + {{chem|X|-}}(aq) → AgX(s)

where {{chem|X|-}} = {{chem|Cl|-}}, {{chem|Br|-}}, or {{chem|I|-}}.

Other silver salts with [[non-coordinating anions]], namely [[silver tetrafluoroborate]] and [[silver hexafluorophosphate]] are used for more demanding applications.

Similarly, this reaction is used in [[analytical chemistry]] to confirm the presence of [[chloride]], [[bromide]], or [[iodide]] [[ions]]. Samples are typically acidified with dilute nitric acid to remove interfering ions, e.g. [[carbonate]] ions and [[sulfide]] ions. This step avoids confusion of [[silver sulfide]] or [[silver carbonate]] precipitates with that of silver halides. The color of precipitate varies with the halide: white ([[silver chloride]]), pale yellow/cream ([[silver bromide]]), yellow ([[silver iodide]]). AgBr and especially AgI [[photochemistry|photo-decompose]] to the metal, as evidenced by a grayish color on exposed samples.

The same reaction was used on steamships in order to determine whether or not [[boiler feedwater]] had been contaminated with [[seawater]]. It is still used to determine if moisture on formerly dry cargo is a result of [[condensation]] from humid air, or from seawater leaking through the hull.<ref>{{cite web| title =Silver nitrate method| website =Transport Information Service| publisher =Gesamtverband der Deutschen Versicherungswirtschaf| url =http://www.tis-gdv.de/tis_e/misc/silber.htm| access-date = 22 June 2015 }}</ref>

===Organic synthesis===
Silver nitrate is used in many ways in [[organic synthesis]], e.g. for [[deprotection]] and oxidations. {{chem|Ag|+}} binds [[alkene]]s reversibly, and silver nitrate has been used to separate mixtures of alkenes by selective absorption. The resulting [[adduct]] can be decomposed with [[ammonia]] to release the free alkene.<ref>{{OrgSynth|author = Cope, A. C.; Bach, R. D.|title = trans-Cyclooctene|collvol = 5|collvolpages = 315|year = 1973|prep = cv5p0315}}</ref> Silver nitrate is highly soluble in water but is poorly soluble in most organic solvents, except [[acetonitrile]] (111.8 g/100 g, 25 °C).<ref>{{Cite web|url=http://chemister.ru/Database/properties-en.php?id=862|title=silver nitrate|website=chemister.ru|access-date=2019-04-04}}</ref>

===Biology===
In [[histology]], silver nitrate is used for [[silver stain]]ing, for demonstrating reticular fibers, [[protein]]s and [[nucleic acid]]s. For this reason it is also used to demonstrate proteins in [[polyacrylamide gel electrophoresis]] (PAGE) gels. It can be used as a stain in [[scanning electron microscopy]].<ref>{{cite journal|author = Geissinger HD|title = The use of silver nitrate as a stain for scanning electron microscopy of arterial intima and paraffin sections of kidney|journal = Journal of Microscopy|volume = 95|issue = 3|pages = 471–481|year = 2011|doi = 10.1111/j.1365-2818.1972.tb01051.x|pmid = 4114959|s2cid = 38335416}}</ref>

Cut flower stems can be placed in a silver nitrate solution, which prevents the production of ethylene. This delays ageing of the flower.<ref>{{Cite web |title=Silver Nitrate (072503) Fact Sheet |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-072503_01-Oct-01.pdf |access-date=3 October 2024 |website=epa.gov}}</ref>

=== Indelible ink ===
Silver nitrate produces long-lasting stain when applied to skin and is one of indelible ink’s ingredients. An [[Election ink|electoral stain]] makes use of this to mark a finger of people who have voted in an election, allowing easy identification to prevent double-voting.<ref>{{Cite news |date=2023-06-17 |title=The ink with a 'secret formula' that powers the world's biggest democratic exercise {{!}} India {{!}} The Guardian |newspaper=The Guardian |url=https://www.theguardian.com/world/2019/mar/28/india-the-ink-with-a-secret-formula-that-powers-the-worlds-biggest-democratic-exercise |access-date=2024-04-17 |archive-url=https://web.archive.org/web/20230617165311/https://www.theguardian.com/world/2019/mar/28/india-the-ink-with-a-secret-formula-that-powers-the-worlds-biggest-democratic-exercise |archive-date=2023-06-17 |last1=Dhillon |first1=Amrit }}</ref><ref>{{Cite news |last=Dhillon |first=Amrit |date=2019-03-28 |title=The ink with a 'secret formula' that powers the world's biggest democratic exercise |url=https://www.theguardian.com/world/2019/mar/28/india-the-ink-with-a-secret-formula-that-powers-the-worlds-biggest-democratic-exercise |access-date=2024-04-17 |work=The Guardian |language=en-GB |issn=0261-3077}}</ref>{{anchor|medical}}

In addition to staining skin, silver nitrate has a history of use in stained glass. In the 14th century, artists began using a "silver stain" (also known as a yellow stain) made from silver nitrate to create a yellow effect on clear glass. The stain would produce a stable color that could range from pale lemon to deep orange or gold. Silver stain was often used with glass paint, and was applied to the opposite side of the glass as the paint. It was also used to create a mosaic effect by reducing the number of pieces of glass in a window. Despite the age of the technique, this process of creating stained glass remains almost entirely unchanged.<ref>{{Cite web |title=Khan Academy |url=https://www.khanacademy.org/humanities/medieval-world/gothic-art/beginners-guide-gothic-art/a/stained-glass-history-and-technique#:~:text=Why%20is%20it%20called%20stained,made%20the%20same%20way%20today. |access-date=2024-10-29 |website=www.khanacademy.org |language=en}}</ref>

==Medicine==
{{see also|Medical uses of silver}}
[[Image:Atypical leiomyoma intermed mag.jpg|left|thumb|[[Micrograph]] showing a silver nitrate (brown) marked [[surgical margin]].]]
Silver salts have [[antiseptic]] properties. In 1881 [[Carl Siegmund Franz Credé|Credé]] introduced a method known as [[Credé's prophylaxis]], which used of dilute (2%) solutions of silver nitrate in [[neonate|newborn babies]]' eyes at birth to prevent contraction of [[gonorrhea]] from the mother, which could cause blindness via [[ophthalmia neonatorum]]. (Modern antibiotics are now used instead).<ref name="Mate2013">{{cite journal|last1=Matejcek|first1=A|last2=Goldman|first2=RD|title=Treatment and prevention of ophthalmia neonatorum.|journal=Canadian Family Physician|date=November 2013|volume=59|issue=11|pages=1187–90|pmid=24235191|pmc=3828094}}</ref><ref>{{cite journal| author = Peter.H| title = Dr Carl Credé (1819–1892) and the prevention of ophthalmia neonatorum| journal = Arch Dis Child Fetal Neonatal Ed| volume = 83| year = 2000| pages = F158–F159| doi = 10.1136/fn.83.2.F158| pmid = 10952715| issue = 2| pmc = 1721147}}</ref><ref>{{cite journal| author = Credé C. S. E.| title = Die Verhürtung der Augenentzündung der Neugeborenen| journal = Archiv für Gynäkologie| volume = 17| year = 1881| issue = 1| pages = 50–53| doi = 10.1007/BF01977793| s2cid = 10053605}}</ref><ref name=Ulrich>{{cite journal|url=https://www.scielosp.org/article/bwho/2001.v79n3/262-266/en/|journal=Bulletin of the World Health Organization|title=Is Credés prophylaxis for ophthalmia neonatorum still valid?|author1=Schaller, Ulrich C. |author2=Klauss, Volker |name-list-style=amp |volume=79 |issue=3|year=2001|pages=262–266|pmid=11285676|pmc=2566367}}</ref>

Fused silver nitrate, shaped into sticks, was traditionally called "lunar caustic". It is used as a [[cauterization|cauterizing]] agent, for example to remove [[granulation tissue]] around a [[Stoma (medicine)|stoma]]. General [[James Abbott (Indian Army officer)|Sir James Abbott]] noted in his journals that in India in 1827 it was infused by a British surgeon into wounds in his arm resulting from the bite of a mad dog to cauterize the wounds and prevent the onset of rabies.<ref>British Library, India Office Records, European Manuscripts, MSS EUR F171/33/3, page 109.</ref>

Silver nitrate is used to cauterize superficial blood vessels in the nose to help prevent [[nosebleed]]s.

Dentists sometimes use silver nitrate-infused swabs to heal [[oral ulcer]]s. Silver nitrate is used by some [[podiatrist]]s to kill cells located in the nail bed.

The Canadian physician C. A. Douglas Ringrose researched the use of silver nitrate for [[Human sterilization (surgical procedure)|sterilization procedures]], believing that silver nitrate could be used to block and corrode the fallopian tubes.<ref>{{cite journal|journal=Obstetrics and Gynecology|volume=42|issue=1|pages=151–5|year=1973 |author=Ringrose CA.|title=Office tubal sterilization|pmid=4720201}}</ref> The technique was ineffective.<ref>Cryderman v. Ringrose (1978), 89 D.L.R. (3d) 32 (Alta S.C.) and Zimmer et al. v. Ringrose (1981) 4 W.W.R. 75 (Alta C.A.).</ref>

===Disinfection===
Much research has been done in evaluating the ability of the silver ion at inactivating ''[[Escherichia coli]]'', a microorganism commonly used as an indicator for fecal contamination and as a surrogate for pathogens in drinking water treatment. Concentrations of silver nitrate evaluated in inactivation experiments range from 10–200 micrograms per liter as Ag+.
Silver's antimicrobial activity saw many applications prior to the discovery of modern antibiotics, when it fell into near disuse. Its association with [[argyria]] made consumers wary and led them to turn away from it when given an alternative.{{cn|date=September 2023}}

===Against warts===
[[Image:Silver nitrate stains.jpg|thumb|right|Skin stained by silver nitrate]]
Repeated daily application of silver nitrate can induce adequate destruction of cutaneous [[warts]], but occasionally pigmented scars may develop. In a placebo-controlled study of 70 patients, silver nitrate given over nine days resulted in clearance of all warts in 43% and improvement in warts in 26% one month after treatment compared to 11% and 14%, respectively, in the placebo group.<ref>{{Cite journal | issue = 1 | volume = 144 | journal = British Journal of Dermatology | pages = 4–11 | year = 2001 | url = http://www.huidziekten.nl/richtlijnen/BADguidelineCutaneousWarts2001.pdf | pmid = 11167676 | doi = 10.1046/j.1365-2133.2001.04066.x | title = Guidelines for the management of cutaneous warts | first2 = S. | last2 = Handfield-Jones | last1 = Sterling | last3 = Hudson | author4 = British Association of Dermatologists | first1 = J. C. | first3 = P. M. | s2cid = 20179474 | url-status = dead | archive-url = https://web.archive.org/web/20120303031317/http://www.huidziekten.nl/richtlijnen/BADguidelineCutaneousWarts2001.pdf | archive-date = 2012-03-03 }}</ref>

==Safety==
As an oxidant, silver nitrate should be properly stored away from organic compounds. It reacts explosively with ethanol.<ref>{{Cite journal |last1=Perrin |first1=D. D. |last2=Armarego |first2=W. L. F. |last3=Perrin |first3=D. R. |date=November 1986 |title=Silver nitrate + ethanol = explosion |url=https://pubs.acs.org/doi/abs/10.1021/ed063p1016.1 |journal=Journal of Chemical Education |language=en |volume=63 |issue=11 |pages=1016 |doi=10.1021/ed063p1016.1 |bibcode=1986JChEd..63.1016P |issn=0021-9584|url-access=subscription }}</ref> Despite its common usage in extremely low concentrations to prevent [[gonorrhea]] and control nosebleeds, silver nitrate is still very toxic and corrosive.<ref>{{cite web|url=http://msds.chem.ox.ac.uk/SI/silver_nitrate.html|title=Safety data for silver nitrate (MSDS)|publisher=Oxford University Chemistry department|access-date=2008-03-25|archive-date=2011-12-02|archive-url=https://web.archive.org/web/20111202090543/http://msds.chem.ox.ac.uk/SI/silver_nitrate.html|url-status=dead}}</ref> Brief exposure will not produce any immediate side effects other than the purple, brown or black stains on the skin, but upon constant exposure to high concentrations, side effects will be noticeable, which include burns. Long-term exposure may cause eye damage. Silver nitrate is known to be a skin and eye irritant. Silver nitrate has not been thoroughly investigated for potential [[carcinogen|carcinogenic effect]].<ref>{{cite web|title= New Jersey Right-To-Know-Act Hazardous Substance Fact Sheet - Silver Nitrate|url=http://nj.gov/health/eoh/rtkweb/documents/fs/1672.pdf}}</ref>

Silver nitrate is currently unregulated in water sources by the United States Environmental Protection Agency. However, if more than 1 gram of silver is accumulated in the body, a condition called [[argyria]] may develop. Argyria is a permanent cosmetic condition in which the skin and internal organs turn a blue-gray color. The United States Environmental Protection Agency used to have a maximum contaminant limit for silver in water until 1990, when it was determined that argyria did not impact the function of any affected organs despite the discolouration.<ref name="silver compounds">"Silver Compounds." Encyclopedia of Chemical Technology. Vol. 22. Fourth Ed. Excec. Ed. Jaqueline I. Kroschwitz. New York: John Wiley and Sons, 1997.</ref> Argyria is more often associated with the consumption of [[colloidal silver]] solutions rather than with silver nitrate, since it is only used at extremely low concentrations to disinfect the water. However, it is still important to be wary before ingesting any sort of silver-ion solution.

==References==
{{reflist}}

==External links==
{{Commons category}}
* [http://www.inchem.org/documents/icsc/icsc/eics1116.htm International Chemical Safety Card 1116]
* [https://www.cdc.gov/niosh/npg/npgd0557.html NIOSH Pocket Guide to Chemical Hazards]
* [https://web.archive.org/web/20031205232245/http://www.kodak.com/US/en/corp/aboutKodak/kodakHistory/filmImaging.shtml History of Kodak: About Film and Imaging]
https://www.cofesilver.com/en/silver_bar :silver bar explanation. pricing investing
{{Silver compounds}}
{{Nitrates}}
{{Antiseptics and disinfectants}}
{{Authority control}}

[[Category:13th century in science]]
[[Category:Antiseptics]]
[[Category:Electron microscopy stains]]
[[Category:Nitrates]]
[[Category:Photographic chemicals]]
[[Category:Silver compounds]]
[[Category:Staining dyes]]
[[Category:Alchemical substances]]
[[Category:Light-sensitive chemicals]]
[[Category:Oxidizing agents]]
[[Category:Chemical tests]]

Dibromomethane

2025-05-28T14:09:12Z

150.128.167.154: Rectified technicality, added nbsp and removed excess spaces

{{Chembox
| Watchedfields = changed
| verifiedrevid = 445810807
| ImageFile = Natta projection of dibromomethane.svg
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageSize = 150
| ImageName =
| ImageFile1 = Dibromomethane 3D.png
| ImageFile1_Ref = {{chemboximage|correct|??}}
| ImageSize1 = 100
| ImageName1 = Spacefill model for dibromomethane
| PIN = Dibromomethane<ref>{{Cite web|title=methylene bromide - Compound Summary|url=https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3024&loc=ec_rcs#x291|work=PubChem Compound|publisher=National Center for Biotechnology Information|access-date=18 June 2012|location=USA|date=25 March 2005|at=Identification}}</ref>
| OtherNames = {{Unbulleted list|Methyl dibromide|Methylene bromide|Methylene dibromide|Refrigerant-30B2{{Citation needed|date=June 2012}}
}}
|Section1={{Chembox Identifiers
| Abbreviations = {{Unbulleted list|DBM{{Citation needed|date=June 2012}}|MDB{{Citation needed|date=June 2012}}|UN 2664{{Citation needed|date=June 2012}}}}
| CASNo = 74-95-3
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = V69B659W01
| PubChem = 3024
| ChemSpiderID = 2916
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 200-824-2
| UNNumber = 2664
| MeSHName = methylene+bromide
| ChEBI = 47077
| ChEBI_Ref = {{ebicite|correct|EBI}}
| RTECS = PA7350000
| Beilstein = 969143
| Gmelin = 25649
| SMILES = BrCBr
| StdInChI = 1S/CH2Br2/c2-1-3/h1H2
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = FJBFPHVGVWTDIP-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| C=1 | H=2 | Br=2
| Appearance = Colorless to yellow liquid
| Density = 2.477 g⋅mL−1
| MeltingPtK = 220.45
| BoilingPtK = 369 to 371
| Solubility = 12.5 g⋅L−1 (at 20 °C)
| VaporPressure = 4.65 kPa (at 20.0 °C)
| HenryConstant = 9.3 μmol⋅Pa−1⋅kg−1
| RefractIndex = 1.541
| MagSus = −65.10·10−6⋅cm3/mol
}}
|Section3={{Chembox Thermochemistry
| HeatCapacity = 104.1 J⋅K−1⋅mol−1
}}
|Section4={{Chembox Hazards
| GHSPictograms = {{GHS exclamation mark}}
| GHSSignalWord = '''WARNING'''
| HPhrases = {{H-phrases|332|412}}
| PPhrases = {{P-phrases|273}}
| NFPA-H = 2
| NFPA-F = 0
| NFPA-R = 0
| LD50 = {{ubli
| 1 g⋅kg−1 (oral, rabbit)
| 3.738 g⋅kg−1 (subcutaneous, mouse)
| >4 g⋅kg−1 (dermal, rabbit)
}}
}}
|Section5={{Chembox Related
| OtherFunction_label = alkanes
| OtherFunction = {{ubl
| [[Bromoform]]
| [[Tetrabromomethane]]
| [[1,1-Dibromoethane]]
| [[1,2-Dibromoethane]]}}
}}
}}
'''Dibromomethane''' or '''methylene bromide''', or '''methylene dibromide''' is a [[halomethane]] with the formula CH2Br2. It is slightly soluble in water but very soluble in [[organic solvents]]. It is a colorless liquid.

==Physical properties==
At ambient temperature, dibromomethane solidifies around 0.61 [[Gigapascal|GPa]]. The crystal structure strongly suggests both interhalogen and hydrogen-halogen interactions.<ref name=Crystals />

==Preparation==
Dibromomethane is prepared commercially from dichloromethane via [[bromochloromethane]]:
:6 CH2Cl2 + 3 Br2 + 2 Al → 6 CH2BrCl + 2 AlCl3
:CH2Cl2 + HBr → CH2BrCl + HCl
The latter route requires [[aluminium trichloride]] as a catalyst.<ref name=Ullmann>{{ Ullmann | author = Dagani, M. J. | author2 = Barda, H. J. | author3 = Benya, T. J. | author4 = Sanders, D. C. | title = Bromine Compounds | doi = 10.1002/14356007.a04_405 }}</ref>
The bromochloromethane product from either reaction can further react in a similar manner:
:6 CH2BrCl + 3 Br2 + 2 Al → 6 CH2Br2 + 2 AlCl3
:CH2BrCl + HBr → CH2Br2 + HCl

In the laboratory, it is prepared from [[bromoform]] using [[sodium arsenite]] and [[sodium hydroxide]]:<ref>{{cite journal|title=Methylene bromide|journal=Org. Synth.|year=1929|volume=9|page=56|doi=10.15227/orgsyn.009.0056|author=W. W. Hartman, E. E. Dreger}}</ref>
:CHBr3 + Na3AsO3 + NaOH → CH2Br2 + Na3AsO4 + NaBr

Another way is to prepare it from [[diiodomethane]] and [[bromine]].

==Uses==
Dibromomethane is used as a [[solvent]], gauge fluid, and in [[organic synthesis]] (often as [[Proton_nuclear_magnetic_resonance|1H-NMR]] [[internal standard]]).<ref name=Ullmann/> It conviently converts [[polyol]]s (such as [[catechols]]) to their [[methylenedioxy]] derivatives, and bromomethylenates [[enolate]]s. It is a much cheaper precursor to a [[Simmons-Smith]]-type reagent than [[diiodomethane]].<ref>{{cite encyclopedia|doi=10.1002/047084289X.rd044|entry=Dibromomethane|first=Donald S.|last=Matteson|encyclopedia=[[Encyclopedia of Reagents for Organic Synthesis]]}}</ref>

==Natural occurrence==
It is naturally produced by marine [[algae]] and liberated to the oceans. Releasing on soil causes it to evaporate and leach into the ground. Releasing in water causes it to be lost mainly by [[volatilisation]] with a half life of 5.2 hours. It has no significant degradation biological or abiological effects. In the atmosphere it will be lost because of reaction with photochemically produced [[hydroxyl]] radicals. The estimated half life of this reaction is 213 days.

==References==
<references>
<ref name=Crystals>{{cite journal |author1=Podsiadlo M. |author2=Dziubek K. |author3=Szafranski M. |author4=Katrusiak A. | date = December 2006 | title = Molecular interactions in crystalline dibromomethane and diiodomethane, and the stabilities of their high-pressure and low-temperature phases | journal = Acta Crystallogr. B | volume = 62 | issue = 6 | pages = 1090–1098(9) | pmid = 17108664| doi = 10.1107/S0108768106034963 | url = https://www.researchgate.net/profile/Marek-Szafranski-2/publication/6688553_Molecular_interactions_in_crystalline_dibromomethane_and_diiodomethane_and_the_stabilities_of_their_high-pressure_and_low-temperature_phases/links/09e41510f72dc4ba1e000000/Molecular-interactions-in-crystalline-dibromomethane-and-diiodomethane-and-the-stabilities-of-their-high-pressure-and-low-temperature-phases.pdf | access-date = 2007-06-29 }}</ref>
</references>

==External links==
* {{ICSC|0354|03}}

{{Halomethanes}}

[[Category:Bromoalkanes]]
[[Category:Halomethanes]]
[[Category:Refrigerants]]