Everything about Silver Nitrate totally explained
| Section2 =
| Section7 =,,
| SPhrases =,,,
,
}}
}}
Silver nitrate is a soluble
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 AgNO
3 solution on the skin results in a white stain which turns dark after exposure to sunlight(UV radiation), after long periods of no sunlight the stain may revert back to white/light purple. The stain usually goes away as the skin peels, which takes about 1.5 weeks. It is also possible to use a nail file to rub the stained skin away.
Chemistry
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:
» 4Ag(s) + 6HNO
3(aq) → 4AgNO
3(aq) + 3H
2O(l) + NO(g) + NO
2(g)
In solid silver nitrate, the silver ions are three-coordinated in a trigonal planar arrangement.
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
silver fluoroborate and
silver perchlorate. It is relatively stable to light. Finally it dissolves in numerous solvents. The nitrate can be easily replaced by other ligands, rendering AgNO
3 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 AgNO
3 + 2 NaOH → Ag
2O + 2 NaNO
3 + H
2O
Organic synthesis
Silver nitrate is used in many ways in
organic synthesis, for example 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.
Medicine
Silver salts have
antiseptic properties. AgNO
3 is often 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 protection was first used by
Credé in 1881 and is still in use.
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. 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.
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". The technique was ineffective; in fact at least two women underwent abortions. Ringrose was sued for malpractice, although these suits were unsuccessful.
Biology
In
histology, silver nitrate is used for
silver staining, for demonstrating
proteins and
nucleic acids. For this reason it's 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 ions can be tested by adding silver nitrate solution. Samples are typically acidifed with dilute nitric acid to remove interfering ions, for example
carbonate ions and
sulfide ions. This step avoids confusion of
silver sulfide or
silver carbonate precipitates with that of silver halides. Addition of AgNO
3 to the resulting solutions produces a precipitate in the presence of 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.
Coordination chemistry
In aqueous solution, silver nitrate is also often used to abstract halides in the form of the insoluble silver halide salt:
» Ag
+ (aq) + X
- (aq) → AgX (s) (X = Cl, Br, I)
Other silver salts with
non-coordinating anions, namely
silver tetrafluoroborate and
silver hexafluorophosphate are used for more demanding applications.
Toxicity
As with all silver salts, silver nitrate is toxic and corrosive. Little exposure to the chemical won't produce immediate or even any side effects other than the purple skin stains, but with more exposure, side effects will become more noticeable. It is also very poisonous and can cause burns. Long-term exposure can cause permanent blue-grey staining of eyes, mouth, throat and skin, (argyria) and may cause eye damage. Short contact can lead to deposition of black silver stains on the skin. Besides being very destructive of mucous membranes, it's a skin and eye irritant.
Further Information
Get more info on 'Silver Nitrate'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://silver_nitrate.totallyexplained.com">Silver nitrate Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |