Silver oxide

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Silver oxide
Silver(I)-oxide-unit-cell-3D-bs-17.png
Silver(I)-oxide-xtal-3x3x3-3D-bs-17.png
Silver oxide.jpg
Names
IUPAC name
Silver(I) oxide
Other names
Silver rust, Argentous oxide, Silver monoxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.039.946 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 243-957-1
MeSH silver+oxide
PubChem CID
RTECS number
  • VW4900000
UNII
  • InChI=1S/2Ag.O/q2*+1;-2 X mark.svgN
    Key: NDVLTYZPCACLMA-UHFFFAOYSA-N X mark.svgN
  • InChI=1S/2Ag.O/q2*+1;-2
    Key: NDVLTYZPCACLMA-UHFFFAOYSA-N
  • [O-2].[Ag+].[Ag+]
Properties
Ag2O
Molar mass 231.735 g·mol−1
AppearanceBlack/ brown cubic crystals
Odor Odorless [1]
Density 7.14 g/cm3
Melting point 300 °C (572 °F; 573 K) decomposes from ≥200 °C [2] [3]
0.013 g/L (20 °C)
0.025 g/L (25 °C) [4]
0.053 g/L (80 °C) [2]
Solubility product (Ksp) of AgOH
1.52·10−8 (20 °C)
Solubility Soluble in acid, alkali
Insoluble in ethanol [4]
134.0·10−6 cm3/mol
Structure
Cubic
Pn3m, 224
Thermochemistry
65.9 J/mol·K [4]
Std molar
entropy
(S298)
122 J/mol·K [5]
−31 kJ/mol [5]
−11.3 kJ/mol [3]
Hazards
GHS labelling:
GHS-pictogram-rondflam.svg GHS-pictogram-exclam.svg [6]
Danger
H272, H315, H319, H335 [6]
P220, P261, P305+P351+P338 [6]
NFPA 704 (fire diamond)
[1]
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
0
1
Lethal dose or concentration (LD, LC):
2.82 g/kg (rats, oral) [1]
Related compounds
Related compounds
Silver(I,III) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Silver oxide is the chemical compound with the formula Ag2O. It is a fine black or dark brown powder that is used to prepare other silver compounds.

Contents

Preparation

Silver(I) oxide produced by reacting lithium hydroxide with a very dilute silver nitrate solution Silver(I) oxide.JPG
Silver(I) oxide produced by reacting lithium hydroxide with a very dilute silver nitrate solution

Silver oxide can be prepared by combining aqueous solutions of silver nitrate and an alkali hydroxide. [7] [8] This reaction does not afford appreciable amounts of silver hydroxide due to the favorable energetics for the following reaction: [9]

(pK = 2.875 [10] )

With suitably controlled conditions, this reaction can be used to prepare Ag2O powder with properties suitable for several uses including as a fine grained conductive paste filler. [11]

Structure and properties

Ag2O features linear, two-coordinate Ag centers linked by tetrahedral oxides. It is isostructural with Cu2O. It "dissolves" in solvents that degrade it. It is slightly soluble in water due to the formation of the ion Ag(OH)2 and possibly related hydrolysis products. [12] It is soluble in ammonia solution, producing active compound of Tollens' reagent. A slurry of Ag2O is readily attacked by acids:

where HX = HF, HCl, HBr, HI, or CF3COOH. It will also react with solutions of alkali chlorides to precipitate silver chloride, leaving a solution of the corresponding alkali hydroxide. [12] [13]

Despite the photosensitivity of many silver compounds, silver oxide is not photosensitive, [14] although it readily decomposes at temperatures above 280 °C. [15]

Applications

This oxide is used in silver-oxide batteries. In organic chemistry, silver oxide is used as a mild oxidizing agent. For example, it oxidizes aldehydes to carboxylic acids. Such reactions often work best when the silver oxide is prepared in situ from silver nitrate and alkali hydroxide.

Related Research Articles

<span class="mw-page-title-main">Hydroxide</span> Chemical compound

Hydroxide is a diatomic anion with chemical formula OH. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.

<span class="mw-page-title-main">Iron(III)</span> The element iron in its +3 oxidation state

In chemistry, iron(III) refers to the element iron in its +3 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe3+.

<span class="mw-page-title-main">Silver nitrate</span> Chemical compound

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

Iron(III) chloride describes the inorganic compounds with the formula FeCl3(H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated forms which are both hygroscopic. They feature iron in its +3 oxidation state. The anhydrous derivative is a Lewis acid, while all forms are mild oxidizing agent. It is used as a water cleaner and as an etchant for metals.

<span class="mw-page-title-main">Potassium ferrate</span> Chemical compound

Potassium ferrate is the chemical compound with the formula K2FeO4. This purple salt is paramagnetic, and is a rare example of an iron(VI) compound. In most of its compounds, iron has the oxidation state +2 or +3 (Fe2+ or Fe3+). Reflecting its high oxidation state, FeO2−4 is a powerful oxidizing agent.

<span class="mw-page-title-main">Tollens' reagent</span> Chemical reagent used to distinguish between aldehydes and ketones

Tollens' reagent is a chemical reagent used to distinguish between aldehydes and ketones along with some alpha-hydroxy ketones which can tautomerize into aldehydes. The reagent consists of a solution of silver nitrate, ammonium hydroxide and some sodium hydroxide. It was named after its discoverer, the German chemist Bernhard Tollens. A positive test with Tollens' reagent is indicated by the precipitation of elemental silver, often producing a characteristic "silver mirror" on the inner surface of the reaction vessel.

<span class="mw-page-title-main">Ferrate(VI)</span> Ion

Ferrate(VI) is the inorganic anion with the chemical formula [FeO4]2−. It is photosensitive, contributes a pale violet colour to compounds and solutions containing it and is one of the strongest water-stable oxidizing species known. Although it is classified as a weak base, concentrated solutions containing ferrate(VI) are corrosive and attack the skin and are only stable at high pH. It is similar to the somewhat more stable permanganate.

<span class="mw-page-title-main">Silver carbonate</span> Chemical compound

Silver carbonate is the chemical compound with the formula Ag2CO3. This salt is yellow but typical samples are grayish due to the presence of elemental silver. It is poorly soluble in water, like most transition metal carbonates.

Basic oxides are oxides that show basic properties in opposition to acidic oxides and that either

<span class="mw-page-title-main">Palladium(II) oxide</span> Chemical compound

Palladium(II) oxide is the inorganic compound of formula PdO. It is the only well characterised oxide of palladium. It is prepared by treating the metal with oxygen. Above about 900 °C, the oxide reverts to palladium metal and oxygen gas. It is not attacked by acids.

<span class="mw-page-title-main">Cadmium nitrate</span> Chemical compound

Cadmium nitrate describes any of the related members of a family of inorganic compounds with the general formula , the most commonly encountered form being the tetrahydrate. The anhydrous form is volatile, but the others are colourless crystalline solids that are deliquescent, tending to absorb enough moisture from the air to form an aqueous solution. Like other cadmium compounds, cadmium nitrate is known to be carcinogenic.

<span class="mw-page-title-main">Iron(III) nitrate</span> Chemical compound

Iron(III) nitrate, or ferric nitrate, is the name used for a series of inorganic compounds with the formula Fe(NO3)3.(H2O)n. Most common is the nonahydrate Fe(NO3)3.(H2O)9. The hydrates are all pale colored, water-soluble paramagnetic salts.

<span class="mw-page-title-main">Silver compounds</span> Chemical compounds containing silver

Silver is a relatively unreactive metal, although it can form several compounds. The common oxidation states of silver are (in order of commonness): +1 (the most stable state; for example, silver nitrate, AgNO3); +2 (highly oxidising; for example, silver(II) fluoride, AgF2); and even very rarely +3 (extreme oxidising; for example, potassium tetrafluoroargentate(III), KAgF4). The +3 state requires very strong oxidising agents to attain, such as fluorine or peroxodisulfate, and some silver(III) compounds react with atmospheric moisture and attack glass. Indeed, silver(III) fluoride is usually obtained by reacting silver or silver monofluoride with the strongest known oxidizing agent, krypton difluoride.

<span class="mw-page-title-main">Sodium bismuthate</span> Chemical compound

Sodium bismuthate is an inorganic compound, and a strong oxidiser with chemical formula NaBiO3. It is somewhat hygroscopic, but not soluble in cold water, which can be convenient since the reagent can be easily removed after the reaction. It is one of the few water insoluble sodium salts. Commercial samples may be a mixture of bismuth(V) oxide, sodium carbonate and sodium peroxide.

<span class="mw-page-title-main">Metal halides</span>

Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. A few metal halides are discrete molecules, such as uranium hexafluoride, but most adopt polymeric structures, such as palladium chloride.

<span class="mw-page-title-main">Lead compounds</span> Type of compound

Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.

Chromium(III) hydroxide is a gelatinous green inorganic compound with the chemical formula Cr(OH)3. It is a polymer with an undefined structure and low solubility. It is amphoteric, dissolving in both strong alkalis and strong acids.

Germanium(II) hydroxide, normally written as Ge(OH)2, is a poorly characterised compound, sometimes called hydrous germanium(II) oxide or germanous hydroxide. It was first reported by Winkler in 1886.

Neptunium compounds are compounds containg the element neptunium (Np). Neptunium has five ionic oxidation states ranging from +3 to +7 when forming chemical compounds, which can be simultaneously observed in solutions. It is the heaviest actinide that can lose all its valence electrons in a stable compound. The most stable state in solution is +5, but the valence +4 is preferred in solid neptunium compounds. Neptunium metal is very reactive. Ions of neptunium are prone to hydrolysis and formation of coordination compounds.

<span class="mw-page-title-main">Technetium(IV) oxide</span> Chemical compound

Technetium(IV) oxide, also known as technetium dioxide, is a chemical compound with the formula TcO2 which forms the dihydrate, TcO2·2H2O, which is also known as technetium(IV) hydroxide. It is a radioactive black solid which slowly oxidizes in air.

References

  1. 1 2 3 "Silver Oxide MSDS". SaltLakeMetals.com. Salt Lake Metals. Retrieved 2014-06-08.
  2. 1 2 Perry, Dale L. (1995). Handbook of Inorganic Compounds (illustrated ed.). CRC Press. p. 354. ISBN   0849386713.
  3. 1 2 "Silver oxide".
  4. 1 2 3 Lide, David R. (1998). Handbook of Chemistry and Physics (81 ed.). Boca Raton, FL: CRC Press. pp. 4–83. ISBN   0-8493-0594-2.
  5. 1 2 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN   978-0-618-94690-7.
  6. 1 2 3 Sigma-Aldrich Co., Silver(I) oxide. Retrieved on 2014-06-07.
  7. O. Glemser and H. Sauer "Silver Oxide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1037.
  8. Janssen, D. E.; Wilson, C. V. (1963). "4-Iodoveratrole". Organic Syntheses .{{cite journal}}: CS1 maint: multiple names: authors list (link); Collective Volume, vol. 4, p. 547
  9. Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN   0-12-352651-5.
  10. Biedermann, George; Sillén, Lars Gunnar (1960). "Studies on the Hydrolysis of Metal Ions. Part 30. A Critical Survey of the Solubility Equilibria of Ag2O". Acta Chemica Scandinavica. 13: 717–725. doi: 10.3891/acta.chem.scand.14-0717 .
  11. US 20050050990A1,Harigae, Kenichi&Shoji, Yoshiyuki,"Fine-grain silver oxide powder",published 2005-03-10
  12. 1 2 Cotton, F. Albert; Wilkinson, Geoffrey (1966). Advanced Inorganic Chemistry (2nd Ed.). New York:Interscience. p. 1042.
  13. General Chemistry by Linus Pauling, 1970 Dover ed. p703-704
  14. Herley, P. J.; Prout, E. G. (1960-04-01). "The Thermal Decomposition of Silver Oxide". Journal of the American Chemical Society. 82 (7): 1540–1543. doi:10.1021/ja01492a006. ISSN   0002-7863.
  15. Merck Index of Chemicals and Drugs Archived 2009-02-01 at the Wayback Machine , 14th ed. monograph 8521