Silver oxide

Silver oxide. Chemical compound of the formula Ag 2 O. It is a fine black or dark brown powder, used to prepare other silver compounds.

Summary

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  • 1 Silver
  • 2 Obtaining
  • 3 Structure and properties
  • 4 Features
  • 5 Properties
  • 6 Applications
  • 7 Uses
  • 8 External links
  • 9 Sources

Silver

Silver is a chemical element with an atomic number 47 located in group 1b of the periodic table of the elements. Its symbol is Ag (comes from the Latin: argentum, from the Indo-European root * arg-for “whites” or “brilliant”

It is found in nature as part of different minerals (generally in the form of sulfur) or as free silver. It is very rare in nature, of which it represents a part in 10 million of the earth’s crust. Most of its production is obtained as a by-product of the treatment of copper , zinc , lead and gold mines . Metallurgy from its minerals is mainly carried out by cyanidation:

Ag 2 S + 4 KCN = K 2 S + 2 KAg (CN) 2

Obtaining

The oxide of silver is commercially available. It can be easily prepared by combining aqueous solutions of silver nitrate and an alkaline hydroxide.3 It is worth noting the fact that this reaction does not provide an appreciable amount of silver hydroxide due to the favorable energy for the following reaction: 4

2 AgOH = Ag 2 O + H 2 O (pK = 2.8755)

Structure and properties

Like most binary oxides, Ag 2 O is a three-dimensional polymer with a covalent bond bonding metal with oxide. It is isostructural with Cu2O, that is to say that they share the same structure, for which reason Ag 2 O is expected to be insoluble in all solvents, 6 except through a reaction. Furthermore, it is evident that it is soluble in aqueous solutions due to the formation of the Ag (OH) 2– ion and is possibly related to hydrolysis products . It dissolves in an ammonium hydroxide solution producing soluble derivatives.

An aqueous compound of Ag 2 O is immediately attacked by acids:

Ag 2 O + 2 HX = 2 AgX + H 2 O

Where HX is equal to HF, HCl, HBr, HI or HO 2 CCF 3 . It also reacts with alkali chloride solutions to precipitate silver chloride, leaving a solution of the corresponding alkali hydroxide.8 7 Silver oxide is photosensitive, and decomposes at temperatures below 280 ° C.

characteristics

Ag 2 O is the formula for silver oxide. It is a three-dimensional polymer with a covalent bond in which the metal joins the oxide. It dissolves in ammonium hydroxide solution. Silver oxide is obtained by the aqueous combination of silver nitrate and an alkali hydroxide.

It is made up of two elements:

  • Silver(Ag): works with valence 1.
  • Oxygen(O): works with valence 2.

Properties

The main properties of Ag2O are:

  • Density: 7140 Kg / m3.
  • Molar mass: 231,735 g / mol.
  • Melting point: 277 ºC.

Applications

  • Commercially, silver oxide is used in silver oxide batteries. In organic chemistry it is used as a mild oxidizing agent, for example, it oxidizes aldehydes to carboxylic acids. Such reactions often work best if silver oxide is prepared in situ from silver nitrate and alkali hydroxide.
  • Of the world’s silver production, approximately 70% is used for industrial purposes, and 30% for monetary purposes, much of this metal is used in goldsmithing, but its most important uses are in the photographic, chemical, medical, and electronics

Applications

  • Melee or melee weapons such as swords, spears, or arrowheads
  • Photography. Due to its sensitivity to light (especially bromide and iodide, as well as phosphate). Silver iodide has also been used to produce artificial rain.
  • Medicine. Despite lacking toxicity, it is mostly applicable in external use. An example is silver nitrate, used to remove warts.
  • Electricity. The contacts of electric generators of diesel-electric locomotives have pure silver contacts (approx. 1 in. Thick); And those machines have an electric motor on each wheel or axle. The diesel engine drives the electricity generator, and you must also add the best quality household key or push button contacts that do not use only copper (more economical).
  • In electronics, due to its high conductivity it is increasingly used, for example, in the contacts of integrated circuits and computer keyboards.
  • Manufacture of mirrors with high reflectivity of visible light (common ones are made of aluminum).
  • Silver has been used to make coins since 700 BC. C., initially with electrum, natural gold and silver alloy, and later pure silver.
  • In jewelry and silverware to manufacture a wide variety of ornamental and everyday household items, and with a lower degree of purity, in jewelryitems .
  • In alloysfor dental pieces.
  • Catalyst in oxidation reactions. For example, in the production of formaldehyde from methanol and oxygen.
  • High capacity solder alloys, electrical contacts and silver-zinc and silver-cadmium batteries.
  • In most sports competitions, a silver medal is awarded to the competition’s runner-up (a gold medal is awarded to the champion and a bronze medal is awarded to third place).
  • Popular folklore attributes magical properties to silver to defeat supernatural creatures such as vampires and werewolves, traditionally with a bullet made of this metal.
  • In the assembly of computers, compounds consisting mainly of pure silver are usually used to join the microprocessor board to the base of the heatsink, and thus cool the processor, due to its heat conductive properties.

 

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