silver halide

Examples of silver halide in the following topics:

• Silver

  • The other silver halides used in the manufacture of photographic emulsions are made in the same way, using bromide or iodide salts.
  • Silver halides are highly insoluble in aqueous solutions and are used in gravimetric analytical methods.
  • Silver halides are soluble in solutions of sodium thiosulfate (Na2S2O3), which is used as a photographic fixer.
  • These compounds are used in photography to bleach silver images, converting them to silver halides that can either be fixed with thiosulfate or redeveloped to intensify the original image.
  • Recognize the propensity of silver halides to precipitate out of solution when formed, as well as silver's electrical and thermal conductivity properties

• Holography

  • One of the most common is a film very similar to photographic film (silver halide photographic emulsion), but with a much higher concentration of light-reactive grains, making it capable of the much higher resolution that holograms require.
  • A layer of this recording medium (e.g. silver halide) is attached to a transparent substrate, which is commonly glass, but may also be plastic.

• Halogen Compounds

  • Halogens are highly reactive and can form hydrogen halides, metal halides, organic halides, interhalogens, and polyhalogenated compounds.
  • When in aqueous solution, the hydrogen halides are known as hydrohalic acids.
  • Metal halides are generally obtained through direct combination or, more commonly, through neutralization of a basic metal salt with a hydrohalic acid.
  • Many synthetic organic compounds, such as plastic polymers, as well as a few natural organic compounds, contain halogen atoms; these are known as halogenated compounds, or organic halides.
  • Silver chloride is the precipitate formed when silver nitrate solution is added to chloride solution.

• Substitution and Elimination Reactions of Amines

  • For example, heating an amine with HBr or HI does not normally convert it to the corresponding alkyl halide, as in the case of alcohols and ethers.
  • Since the counter anion in most 4º-ammonium salts is halide, this is often replaced by the more basic hydroxide ion through reaction with silver hydroxide (or silver oxide).
  • For most simple alkyl halides it was proper to envision a balanced transition state, in which there was a synchronous change in all the bonds.
  • Furthermore, the 4º-ammonium substituent is much larger than a halide or hydroxyl group and may perturb the conformations available to substituted beta-carbons.
  • First, it generates a 4º-ammonium halide salt in a manner different from exhaustive methylation.

• Iron, Cobalt, Copper, Nickel, and Zinc

  • Copper is a member of a family of metals known as the "coinage metals," which includes copper, silver, gold, and roentgenium.
  • Copper is the most heavily used of the coinage metals due to its electrical properties, its abundance (compared to silver and gold), and the properties of its brass and bronze alloys.
  • Copper oxidizes—with some difficulty—to the +1 state in halides and an oxide, and to the +2 state in salts such as copper sulfate CuSO4.
  • The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

• Acidity of Terminal Alkynes

  • This increase in acidity permits the isolation of insoluble silver and copper salts of such compounds.
  • Because the acetylide anion is a powerful nucleophile it may displace halide ions from 1º-alkyl halides to give a more highly substituted alkyne as a product (SN2 reaction).
  • Because RC≡C:(–) Na(+) is a very strong base (roughly a billion times stronger than NaOH), its use as a nucleophile in SN2 reactions is limited to 1º-alkyl halides; 2º and 3º-alkyl halides undergo elimination by an E2 mechanism.

• Alkyl Halide Reactions

  • The functional group of alkyl halides is a carbon-halogen bond, the common halogens being fluorine, chlorine, bromine and iodine.
  • and do not share any of the reactivity patterns shown by the other alkyl halides.
  • The second factor to be considered is the relative stability of the corresponding halide anions, which is likely the form in which these electronegative atoms will be replaced.
  • This stability may be estimated from the relative acidities of the H-X acids, assuming that the strongest acid releases the most stable conjugate base (halide anion).

• The Economy and the Silver Solution

  • Proponents of "free silver" believed that the United States economy should be based on silver instead of gold.
  • Supporters of Free Silver were called "Silverites".
  • Everyone agreed that free silver would raise prices.
  • Free silver advocates wanted the mints to accept silver on the same principle, so that anyone would be able to deposit silver bullion at a Mint and in return receive nearly its weight in silver dollars and other currency.
  • The law required the Treasury to buy the silver with a special issue of Treasury Notes that could be redeemed for either silver or gold.

• Variation of Physical Properties Across a Period

  • Many salts are halides; the hal- syllable in halide and halite reflects this correlation.
  • All Group 1 metals form halides that are white solids at room temperature.
  • All of the alkali halides and alkaline earth halides are solids at room temperature and have melting points in the hundreds of degrees centigrade.
  • In contrast, when an alkali halide or alkaline earth halide melts, the resulting liquid is an excellent electrical conductor.
  • This tells us that these molten compounds consist of ions, whereas the non-metal halides do not.

• Silverties Versus Goldbugs

  • This angered the proponents of monetary silver, known as the silverites.
  • A faction of Republicans from western silver mining regions known as the Silver Republicans endorsed Bryan.
  • Silverites belonged to a number of political parties, including the Silver Party, Populist Party, Democratic Party, and the Silver Republican Party.
  • The Silverites advocated free coinage of silver.
  • Many Silverites were from the West, where silver was mined.