Silver nitrate
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| Names | |
|---|---|
| IUPAC name
Silver nitrate
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| Systematic IUPAC name
Silver(I) nitrate | |
| Other names
Nitric acid silver(1+) salt
Lapis infernalis Argentous nitrate | |
| Identifiers | |
3D model (
JSmol ) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
ECHA InfoCard
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100.028.958 |
| EC Number |
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PubChem CID
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RTECS number
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| UNII | |
| UN number | 1493 |
CompTox Dashboard (EPA)
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| Properties | |
| AgNO3 | |
| Molar mass | 169.872 g·mol−1 |
| Appearance | colorless solid |
| Odor | Odorless |
| Density | 4.35 g/cm3 (24 °C) 3.97 g/cm3 (210 °C)[1] |
| Melting point | 209.7 °C (409.5 °F; 482.8 K)[1][3] |
| Boiling point | 440 °C (824 °F; 713 K) decomposes[1] |
| 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)[2] | |
| Solubility | Soluble in acetone,[1] ammonia, ether, glycerol |
| Solubility in acetic acid | 0.776 g/kg (30 °C) 1.244 g/kg (40 °C) 5.503 g/kg (93 °C)[3] |
| Solubility in acetone | 0.35 g/100 g (14 °C) 0.44 g/100 g (18 °C)[2] |
| Solubility in benzene | 0.22 g/kg (35 °C) 0.44 g/kg (40.5 °C)[2] |
| Solubility in ethanol | 3.1 g/100 g (19 °C)[2] |
| Solubility in ethyl acetate | 2.7 g/100 g (20 °C)[3] |
| log P | 0.19 |
| −45.7·10−6 cm3/mol | |
Refractive index (nD)
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1.744 |
| Viscosity | 3.77 cP (244 °C) 3.04 cP (275 °C)[3] |
| Structure | |
| Orthorhombic, oP56[4] | |
| P212121, No. 19[4] | |
| 222[4] | |
a = 6.992(2) Å, b = 7.335(2) Å, c = 10.125(2) Å[4] α = 90°, β = 90°, γ = 90°
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| Thermochemistry | |
Heat capacity (C)
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93.1 J/mol·K[1] |
Std molar
entropy (S⦵298) |
140.9 J/mol·K[1] |
Std enthalpy of (ΔfH⦵298)formation |
−124.4 kJ/mol[1] |
Gibbs free energy (ΔfG⦵)
|
−33.4 kJ/mol[1] |
| Pharmacology | |
| D08AL01 (WHO) | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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Reacts explosively with ethanol. Toxic. Corrosive. |
| GHS labelling: | |
    [5]
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| Danger | |
| H272, H314, H410[5] | |
| P220, P273, P280, P305+P351+P338, P310, P501[5] | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LDLo (lowest published)
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800 mg/kg (rabbit, oral) 20 mg/kg (dog, oral)[6] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Silver nitrate is an inorganic compound with chemical formula AgNO
3. It is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by ancient alchemists who associated silver with the moon.[7] In solid silver nitrate, the silver ions are three-coordinated in a trigonal planar arrangement.[4]
Synthesis and structure
Albertus Magnus, in the 13th century, documented the ability of nitric acid to separate gold and silver by dissolving the silver.[8] 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 + NO
- Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + 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.[4]
Reactions
A typical reaction with silver nitrate is to suspend a rod of
- 2 AgNO3 + Cu → Cu(NO3)2 + 2 Ag
Silver nitrate decomposes when heated:
Qualitatively, decomposition is negligible below the melting point, but becomes appreciable around 250 °C and fully decomposes at 440 °C.[9]
Most metal nitrates thermally decompose to the respective oxides, 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 of silver; it offers several other advantages as well. It is non-
Treatment of silver nitrate with base gives dark grey silver oxide:[10]
- 2 AgNO3 + 2 NaOH → Ag2O + 2 NaNO3 + H2O
Halide abstraction
The silver cation, Ag+
, reacts quickly with halide sources to produce the insoluble silver halide, which is a cream precipitate if Br−
is used, a white precipitate if Cl−
is used and a yellow precipitate if I−
is used. This reaction is commonly used in inorganic chemistry to abstract halides:
- Ag+
(aq) + X−
(aq) → AgX(s)
where X−
= Cl−
, Br−
, or I−
.
Other silver salts with
Similarly, this reaction is used in
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.[11]
Organic synthesis
Silver nitrate is used in many ways in
binds alkenes 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.[12] Silver nitrate is highly soluble in water but is poorly soluble in most organic solvents, except acetonitrile (111.8 g/100 g, 25 °C).[13]
Biology
In
Indelible ink
Silver nitrate produces long-lasting stain when applied to skin and is one of the ink’s ingredients. An 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.[15][16]
Medicine
Silver salts have
Fused silver nitrate, shaped into sticks, was traditionally called "lunar caustic". It is used as a cauterizing agent, for example to remove granulation tissue around a stoma. General 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.[20]
Silver nitrate is used to cauterize superficial blood vessels in the nose to help prevent nosebleeds.
Dentists sometimes use silver nitrate-infused swabs to heal
The Canadian physician C. A. Douglas Ringrose researched the use of silver nitrate for
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.[citation needed]
Against warts
Repeated daily application of silver nitrate can induce adequate destruction of cutaneous
Safety
As an oxidant, silver nitrate should be properly stored away from organic compounds. Despite its common usage in extremely low concentrations to prevent gonorrhea and control nosebleeds, silver nitrate is still very toxic and corrosive.[24] 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 carcinogenic effect.[25]
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
References
- ^ ISBN 978-1-4200-9084-0.
- ^ a b c d Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). New York City: D. Van Nostrand Company. pp. 617–619.
- ^ a b c d Kiper, Ruslan Anatolievich. "silver nitrate". Chemister.ru. Retrieved 2014-07-20.
- ^ .
- ^ a b c Sigma-Aldrich Co., Silver nitrate. Retrieved on 2014-07-20.
- ^ "Silver (metal dust and soluble compounds, as Ag)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ "Definition of Lunar Caustic". dictionary.die.net. Archived from the original on 2012-01-31.
- ISBN 978-2-88124-569-5.
- S2CID 95532988.
- ^ Campaigne, E.; LeSuer, W. M. (1963). "3-Thiophenecarboxylic (Thenoic) Acid". Organic Syntheses
{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 4, p. 919. (preparation of Ag2O, used in oxidation of an aldehyde) - ^ "Silver nitrate method". Transport Information Service. Gesamtverband der Deutschen Versicherungswirtschaf. Retrieved 22 June 2015.
- ^ Cope, A. C.; Bach, R. D. (1973). "trans-Cyclooctene". Organic Syntheses
{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 5, p. 315. - ^ "silver nitrate". chemister.ru. Retrieved 2019-04-04.
- S2CID 38335416.
- ^ "The ink with a 'secret formula' that powers the world's biggest democratic exercise | India | The Guardian". web.archive.org. 2023-06-17. Retrieved 2024-04-17.
- ISSN 0261-3077. Retrieved 2024-04-17.
- PMID 10952715.
- S2CID 10053605.
- PMID 11285676.
- ^ British Library, India Office Records, European Manuscripts, MSS EUR F171/33/3, page 109.
- PMID 4720201.
- ^ 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.).
- S2CID 20179474. Archived from the original(PDF) on 2012-03-03.
- ^ "Safety data for silver nitrate (MSDS)". Oxford University Chemistry department. Archived from the original on 2011-12-02. Retrieved 2008-03-25.
- ^ "New Jersey Right-To-Know-Act Hazardous Substance Fact Sheet - Silver Nitrate" (PDF).
- ^ "Silver Compounds." Encyclopedia of Chemical Technology. Vol. 22. Fourth Ed. Excec. Ed. Jaqueline I. Kroschwitz. New York: John Wiley and Sons, 1997.
External links
