العربية
中国
Français
Deutsch
Ελληνική
हिन्दी
Italiano
日本語
Português
Русский
EspañolSILVER NITRATE
| R-phrases
| ,,
|-
| S-phrases
| , , ,
,
|-
'Silver nitrate' is a chemical compound with chemical formula AgNO3. This nitrate of silver is a versatile precursor to many silver compounds, such as those used in photography, although this salt is far less sensitive to light than the halides. A spill of AgNO3 on the skin results in a dark stain resulting from a combination of silver metal and silver sulfide.
Finger stained by silver nitrate
| Contents |
| Synthesis and structure |
| Applications |
| Precursor to other silver compounds |
| Organic synthesis |
| Medicine |
| Biology |
| Analytical chemistry |
| Toxicity |
| In fiction |
| References |
| External links |
Synthesis and structure
Silver nitrate crystals can be produced by dissolving silver metal in a solution of nitric acid and evaporating the solution. The equation is as follows:
: 3 Ag(s) + 4HNO3(aq) → 3 AgNO3(aq) + 2 H2O(l) + NO(g)
In the solid state, the silver ions are three coordinated in a trigonal planar arrangement.[1]
Applications
Precursor to other silver compounds
Silver nitrate is the least expensive salt of silver and offers several other advantages as well. It is non-hygroscopic, in contrast to the fluoroborate and perchlorate salts. It is relatively stable to light. Finally it dissolves in numerous solvents. 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 fulminate, azide, or acetylide, through a precipitation reaction. Treatment of silver nitrate with base gives silver oxide:[2]
:2 AgNO3 + 2 NaOH → Ag2O + 2 NaNO3 + H2O
Organic synthesis
Silver nitrate is used as many ways in organic synthesis, e.g. for deprotection and oxidations. Ag+ 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.[3]
Medicine
Silver salts have antiseptic properties. AgNO3 is sometimes dropped into newborn babies' eyes at birth to prevent contraction of gonorrhoea or chlamydia from the mother. Eye infections and blindness of newborns is reduced by this method. This method was invented by Credé in 1881 and is still in use.[4][5][6]
Fused silver nitrate, shaped into sticks, was traditionally called 'lunar caustic'. It is used as a cauterizing agent. The Canadian physician Ringrose researched the use of silver nitrate for sterilization procedures on women. A specialist in obstetrics and gynaecology believed that the corrosive properties of silver nitrate could be used to block and corrode the fallopian tubes, in a process that he called "office tubal sterilization". See 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.). The malpractice suits were not successful although the silver nitrate technique was ineffective. (In fact at least two women underwent abortions.)
Dentists sometimes use silver nitrate-infused swabs to heal mouth ulcers.
Biology
In histology, silver nitrate is used for silver staining, for demonstrating proteins and nucleic acids. For this reason it is also used to demonstrate proteins in PAGE gels. It is also used as a stain in scanning electron microscopy.
Analytical chemistry
The presence of chloride, bromide, or iodide can be tested by silver nitrate solution.
Samples are initially acidifed with dilute nitric acid to remove interfering ions, e.g. carbonate ions and sulphite ions. This step avoids confusion of silver sulphide or silver carbonate precipitates with that of silver halides. Addition of AgNO3 to the resulting solutions produces a precipitate in the presence of halides. The color of precipitate allows the identification of the halide: colorless (chloride), pale yellow (bromide), yellow (iodide). AgCl(s) and AgBr(s) turn grey (solid silver formed) upon sunlight due to photochemical decomposition, with a faster rate on AgCl(s).
Toxicity
As with all silver salts, silver nitrate is toxic. see MSDS.
In fiction
★ In The Five People You Meet in Heaven, by Mitch Albom, the Blue Man became blue because he took too much silver nitrate, and the poison turned his skin gray, then blue.
★ In the film Underworld, bullets containing irradiated silver nitrate are used as a weapon against Lycans (werewolves).
★ In the Year Zero Alternate Reality Game, silver nitrate was used in bombs planted by the Angry Sniper.
References
1. P. Meyer, A. Rimsky et R. Chevalier "Structure du nitrate d'argent à pression et température ordinaires. Exemple de cristal parfait" Acta Crystallographica (1978) B34, 1457-1462. doi:10.1107/S0567740878005907.
2. Campaigne, E.; LeSuer, W. M. "3-Thiophenecarboxylic (Thenoic) Acid" Organic Syntheses, Collected Volume 4, p.919 (1963). (preparation of Ag2O, used in oxidation of an aldehyde). http://www.orgsyn.org/orgsyn/pdfs/CV4P0919.pdf
3. Cope, A. C.; Bach, R. D. "trans-Cycloocene" Organic Syntheses, Collected Volume 5, p.315 (1973); Vol. 49, p.39 (1969). http://www.orgsyn.org/orgsyn/pdfs/CV5P0315.pdf
4. Dr Carl Credé (1819-1892) and the prevention of ophthalmia neonatorum, Peter M Dunn, , , Arch Dis Child Fetal Neonatal, 2000
5. Die Verhürtung der Augenentzündung der Neugeborenen, Credé C. S. E., , , Archiv für Gynaekologie, 1881
6. Bulletin of the WHO: Credé's method still valid?
External links
★ International Chemical Safety Card 1116
★ NIOSH Pocket Guide to Chemical Hazards
★ Solubility of Silver Nitrate
★ Silver Nitrate, more information
This article provided by Wikipedia. To edit the contents of this article, click here for original source.
psst.. try this: add to faves
