Silver nitrite

Structural formula
General
Surname	Silver nitrite
other names	Nitrous silver
Molecular formula	AgNO 2
Brief description	white powder or yellow crystals
External identifiers / databases
CAS number 7783-99-5 EC number 232-041-7 ECHA InfoCard 100.029.128 PubChem 160904 Wikidata Q2285874
properties
Molar mass	153.87 g mol −1
Physical state	firmly
density	4.453 g cm −3 (19 ° C)
Melting point	140 ° C
boiling point	thermal decomposition
solubility	sparingly soluble in water (2.75 g l −1 at 15 ° C), (13.63 g l −1 at 60 ° C) Decomposes in boiling water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 272-302-315-319-400 P: 220-273-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Silver nitrite (not to be confused with silver nitrate ) is the silver salt of nitrous acid . It is composed of the Ag ⁺ cation and the nitrite anion NO ₂ ^- .

Extraction and presentation

It can be produced by reacting a solution of silver nitrate with potassium nitrite . A flaky precipitate of silver nitrite falls out:

${\displaystyle \mathrm {AgNO_{3}(aq)+KNO_{2}(aq)\rightarrow \ AgNO_{2}\downarrow +KNO_{3}(aq)} }$

properties

Silver nitrite, AgNO ₂ , forms a colorless to yellowish powder or yellow crystal needles. It is sparingly soluble in cold water , in warm water the solubility is greater, which is why it can be easily recrystallized. Silver nitrite decomposes above 140 ° C with the separation of metallic silver and emission of nitrous gases . Due to the fact that it can be easily oxidized by atmospheric oxygen , it must be stored tightly closed. Under the influence of light, it gradually decomposes into silver and nitrogen dioxide .

Silver nitrite, precipitated from silver nitrate solution with a grain of sodium nitrite, microscopic, polarized light, magnified about 160 times

use

Precipitated and washed silver nitrite can be used by reaction with alkali or alkaline earth chlorides to produce the pure corresponding alkali or alkaline earth nitrites, e.g. B .:

${\displaystyle \mathrm {AgNO_{2}(s)+KCl(aq)\rightarrow \ AgCl\downarrow +KNO_{2}(aq)} }$

Individual evidence

1. ↑ Wilhelm Segerblom: Tables of Properties of Over Fifteen Hundred Common Inorganic Substances. , P. 86. ( limited preview in Google Book search)
2. ↑ ^{a b c d} Mary Eagleson: Concise encyclopedia chemistry , p. 988., ( limited preview in the Google book search)
3. ↑ ^{a b c} H.JM Creighton & WH Ward: Determination of the solubility of silver nitrite and its degree of dissociation in a saturated solution , J. Am. Chem. Soc. , 37, 1915, 2333-2338.
4. ↑ ^{a b} Data sheet Silver nitrite, 99.98% trace metals basis at Sigma-Aldrich , accessed on August 5, 2011 ( PDF ).