World Library  
Flag as Inappropriate
Email this Article
 

Silver nitrate

Silver nitrate
Skeletal formula of silver nitrate
Sample of silver nitrate
Names
IUPAC name
Silver(I) nitrate, Silver nitrate
Other names
Nitric acid silver(1+) salt
Identifiers
 Y
ATC code D08
ChEBI  Y
ChEMBL  Y
ChemSpider  Y
EC number 231-853-9
Jmol-3D images Image
PubChem
RTECS number VW4725000
UNII  Y
UN number 1493
Properties
AgNO3
Molar mass 169.87 g·mol−1
Appearance White 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][2]
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)[3]
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)[2]
Solubility in acetone 0.35 g/100 g (14 °C)
0.44 g/100 g (18 °C)[3]
Solubility in benzene 0.22 g/kg (35 °C)
0.44 g/kg (40.5 °C)[3]
Solubility in ethanol 3.1 g/100 g (19 °C)[3]
Solubility in ethyl acetate 2.7 g/100 g (20 °C)[2]
log P 0.19[4]
−4.57·10−5 cm3/mol[1]
1.744
Viscosity 3.77 cP (244 °C)
3.04 cP (275 °C)[2]
Structure
Orthorhombic, oP56[5]
P212121, No. 19[5]
222[5]
a = 6.992(2) Å, b = 7.335(2) Å, c = 10.125(2) Å[5]
α = 90°, β = 90°, γ = 90°
Thermochemistry
93.1 J/mol·K[1]
140.9 J/mol·K[1]
−124.4 kJ/mol[1]
−33.4 kJ/mol[1]
Hazards
Main hazards Explosively reacts with ethanol. Corrosive.
GHS pictograms The flame-over-circle pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[6]
GHS signal word Danger
H272, H314, H410[6]
P220, P273, P280, P305+351+338, P310, P501[6]
Oxidizing Agent O Corrosive C Dangerous for the Environment (Nature) N
R-phrases R50/53
S-phrases S26, S36/37/39, S45, S60, S61
NFPA 704
[4]
1
3
3
OX
Lethal dose or concentration (LD, LC):
800 mg/kg (rabbit, oral)
20 mg/kg (dog, oral)[7]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 Y  (: Y/N?)

Silver nitrate is an chemical formula AgNO
3
. This compound 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 the ancient alchemists, who believed that silver was associated with the moon.[8]

In solid silver nitrate, the silver ions are three-coordinated in a trigonal planar arrangement.[5]

Contents

  • Discovery 1
  • Synthesis 2
  • Reactions 3
  • Uses 4
    • Precursor to other silver compounds 4.1
    • Halide abstraction 4.2
    • Organic synthesis 4.3
    • Biology 4.4
  • Medicine 5
    • Disinfection 5.1
    • Against warts 5.2
  • Safety 6
  • References 7
  • External links 8

Discovery

Albertus Magnus, in the 13th century, documented the ability of nitric acid to separate gold and silver by dissolving the silver.[9] Magnus noted that the resulting solution of silver nitrate could blacken skin. Its common name at the time was nitric acid silver.

Synthesis

Silver nitrate can be prepared by reacting silver, such as a silver bullion or silver foil, with nitric acid, resulting in silver nitrate, water, and oxides of nitrogen. Reaction byproducts depend 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

This is performed under a fume hood because of toxic nitrogen oxide(s) evolved during the reaction.[10]

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 Ag(s) + O2(g) + 2 NO2(g)

Qualitatively, decomposition is negligible below the melting point, but becomes appreciable around 250 °C and totally decompose at 440 °C.[11]

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-hygroscopic, in contrast to silver fluoroborate and silver perchlorate. It is relatively stable to light. Finally, 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 fulminate, azide, or acetylide, through a precipitation reaction.

Treatment of silver nitrate with base gives dark grey silver oxide:[12]

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+
+ X
(aq) → AgX

where X
= Cl
, Br
, or 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 can be tested by adding silver nitrate solution. 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 photo-decompose to the metal, as evidence by a grayish color on exposed samples.

The same reaction is used on board ships in order to determine whether or not boiler feedwater has been contaminated with seawater. It is also used to determine if moisture on formerly dry cargo is a result of condensation from humid air, or from seawater leaking through the hull.[13]

Organic synthesis

Silver nitrate is used in many ways in 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.[14]

Biology

In histology, silver nitrate is used for silver staining, for demonstrating reticular fibers, proteins and nucleic acids. For this reason it is also used to demonstrate proteins in PAGE gels. It can be used as a stain in scanning electron microscopy.[15]

Medicine

Micrograph showing a silver nitrate (brown) marked surgical margin.

Silver salts have antiseptic properties. Until the development and widespread adoption of antibiotics, dilute solutions of AgNO3 used to be dropped into newborn babies' eyes at birth to prevent contraction of gonorrhea from the mother. Eye infections and blindness of newborns was reduced by this method; incorrect dosage, however, could cause blindness in extreme cases. This protection was first used by Credé in 1881.[16][17][18] 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.[19] Dentists sometimes use silver nitrate infused swabs to heal oral ulcers. Silver nitrate is also used by some podiatrists to kill cells located in the nail bed. Silver nitrate is also used to cauterize superficial blood vessels in the nose to help prevent nose bleeds.

The Canadian physician C. A. Douglas Ringrose researched the use of silver nitrate for sterilization procedures on women. A specialist in obstetrics and gynaecology, Ringrose 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".[20] The technique was ineffective; in fact at least two women underwent abortions. Ringrose was sued for malpractice, although these suits were unsuccessful.[21]

Disinfection

Much research has been done in evaluating the ability of the silver ion at inactivating argyria made consumers wary and led them to turn away from it when given an alternative.

Against warts

Skin on hand 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.[22]

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 nose bleeds, silver nitrate is still very much toxic and corrosive.[23] 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 is currently unregulated in water sources by the Environmental Protection Agency. However, if more than 1 gram of silver is accumulated in the body, a condition called

Salts and covalent derivatives of the Nitrate ion
HNO3 He
LiNO3 Be(NO3)2 B(NO3)4 C N O FNO3 Ne
NaNO3 Mg(NO3)2 Al(NO3)3 Si P S ClONO2 Ar
KNO3 Ca(NO3)2 Sc(NO3)3 Ti(NO3)4 VO(NO3)3 Cr(NO3)3 Mn(NO3)2 Fe(NO3)3 Co(NO3)2,
Co(NO3)3
Ni(NO3)2 Cu(NO3)2 Zn(NO3)2 Ga(NO3)3 Ge As Se Br Kr
RbNO3 Sr(NO3)2 Y Zr(NO3)4 Nb Mo Tc Ru Rh Pd(NO3)2 AgNO3 Cd(NO3)2 In Sn Sb Te I Xe
CsNO3 Ba(NO3)2   Hf Ta W Re Os Ir Pt Au Hg2(NO3)2,
Hg(NO3)2
Tl(NO3)3 Pb(NO3)2 Bi(NO3)3 Po At Rn
Fr Ra   Rf Db Sg Bh Hs Mt Ds Rg Cn Uut Fl Uup Lv Uus Uuo
La Ce(NO3)3,
Ce(NO3)4
Pr Nd Pm Sm Eu Gd(NO3)3 Tb Dy Ho Er Tm Yb Lu
Ac Th Pa UO2(NO3)2 Np Pu Am Cm Bk Cf Es Fm Md No Lr
  • International Chemical Safety Card 1116
  • NIOSH Pocket Guide to Chemical Hazards

External links

  1. ^ a b c d e f g h i Lide, David R., ed. (2009).  
  2. ^ a b c d Anatolievich, Kiper Ruslan. "silver nitrate". http://chemister.ru. Retrieved 2014-07-20. 
  3. ^ a b c d Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.).  
  4. ^ a b "MSDS of Silver sulfate". https://www.fishersci.ca.  
  5. ^ a b c d e Meyer, P.; Rimsky, A.; Chevalier, R. (1978). "Structure du nitrate d'argent à pression et température ordinaires. Example de cristal parfait".  
  6. ^ a b c Sigma-Aldrich Co., Silver nitrate. Retrieved on 2014-07-20.
  7. ^ "Silver (metal dust and soluble compounds, as Ag)". Immediately Dangerous to Life and Health.  
  8. ^ "Definition of Lunar Caustic". dictionary.die.net. 
  9. ^ Szabadváry, Ferenc (1992). History of analytical chemistry. Taylor & Francis. p. 17.  
  10. ^ "Making silver nitrate". http://www.youtube.com. YouTube. 
  11. ^ Stern, K. H. (1972). "High Temperature Properties and Decomposition of Inorganic Salts Part 3, Nitrates and Nitrites". Journal of Physical and Chemical Reference Data 1 (3): 747.  
  12. ^ Campaigne, E.; LeSuer, W. M. (1963). "3-Thiophenecarboxylic (Thenoic) Acid".   (preparation of Ag2O, used in oxidation of an aldehyde)
  13. ^ "Silver nitrate method". Transport Information Service. Gesamtverband der Deutschen Versicherungswirtschaf. Retrieved 22 June 2015. 
  14. ^ Cope, A. C.; Bach, R. D. (1973). "trans-Cyclooctene".  
  15. ^ Geissinger HD (2011). "The use of silver nitrate as a stain for scanning electron microscopy of arterial intima and paraffin sections of kidney". Journal of Microscopy 95 (3): 471–481.  
  16. ^ Peter.H (2000). "Dr Carl Credé (1819–1892) and the prevention of ophthalmia neonatorum". Arch Dis Child Fetal Neonatal 83 (2): F158–F159.  
  17. ^ Credé C. S. E. (1881). "Die Verhürtung der Augenentzündung der Neugeborenen". Archiv für Gynaekologie 17 (1): 50–53.  
  18. ^ Schaller, Ulrich C. and Klauss, Volker (2001). "Is Credé’s prophylaxis for ophthalmia neonatorum still valid?". Bulletin of the World Health Organization 79 (3): 262–266.  
  19. ^ British Library, India Office Records, European Manuscripts, MSS EUR F171/33/3, page 109.
  20. ^ Ringrose CA. (1973). "Office tubal sterilization". Obstetrics and Gynecology 42 (1): 151–5.  
  21. ^ 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.).
  22. ^ Sterling, J. C.; Handfield-Jones, S.; Hudson, P. M.; British Association of Dermatologists (2001). "Guidelines for the management of cutaneous warts" (PDF). British Journal of Dermatology 144 (1): 4–11.  
  23. ^ "Safety data for silver nitrate (MSDS)". Oxford University Chemistry department. 
  24. ^ "Silver Compounds." Encyclopedia of Chemical Technology. Vol. 22. Fourth Ed. Excec. Ed. Jaqueline I. Kroschwitz. New York: John Wiley and Sons, 1997.

References

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. colloidal silver Argyria is more often associated with the consumption of [24]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.