What Is Silver Carbonate?
Silver carbonate, with the chemical formula Ag2CO3, is also known as silver(I) carbonate due to the univalent state of silver in this compound.
It appears as a light yellow to yellow-green powder at room temperature and is synthesized by reacting silver nitrate with a water-soluble carbonate, such as ammonium carbonate.
The reaction typically occurs in an aqueous system, resulting in silver carbonate precipitating as a water-insoluble compound. Its molecular weight is 275.75, and it is identified by CAS number 534-16-7.
Uses of Silver Carbonate
1. As a Catalyst and Reagent
Silver carbonate serves primarily as a catalyst and reagent, including as a precursor for silver salts of organic acids, due to its solubility in organic solvents. Notably, it is used in Fétizon’s reagent, a mild oxidation catalyst, and for regioselective benzylation of carbohydrate derivatives, as well as in palladium-catalyzed oxyarylation of olefins. It also finds application in the staining of biological specimens for pathological tests.
2. In Silver Compounds
As a silver compound, it is utilized in metallic paints for silver mirror compositions and as a substitute for traditional solder in conductive adhesives (silver pastes).
3. As Photocatalysts
Leveraging its response to visible light, silver carbonate is used in the production of visible light-responsive semiconductors and photocatalysts.
Properties of Silver Carbonate
Silver carbonate is characterized by its light yellow to yellowish-green color, which darkens upon exposure to air and light due to partial oxidation. This sensitivity necessitates storage in light-protective conditions, often in brown bottles, to prevent degradation. It is virtually insoluble in water, requiring large volumes of water to dissolve, but dissolves readily in dilute nitric acid, sulfuric acid, ammonia water, and alkaline cyanide solutions. Decomposition occurs at 210-220°C, yielding silver oxide and carbon dioxide, and further heating produces metallic silver.
Other Information on Silver Carbonate
Toxicity, Hazards, and Regulations
Regulated under various safety laws due to its toxicity, silver carbonate necessitates protective equipment during handling. It reacts with strong oxidizers, posing additional safety considerations. In combustion, it produces carbon dioxide and, under incomplete combustion, carbon monoxide, alongside silver oxides, all of which are harmful to human health.