- Silver oxalate is an inorganic compound with the formula Ag₂C₂O₄, composed of silver(I) ions and the oxalate dianion. It appears as a pale yellow to white crystalline powder and is known for being highly photosensitive and thermally unstable, properties that stem from the ease with which the oxalate group decomposes while reducing silver ions to metallic silver. Because of this instability, silver oxalate must be handled with care—especially in dry form—since it can decompose violently when heated or subjected to friction.
- Chemically, silver oxalate is sparingly soluble in water, as the lattice energy of the compound is quite high and the oxalate ion does not sufficiently stabilize the silver ions in solution. However, it dissolves more readily in ammonia or basic solutions due to the formation of silver-ammonia complexes or silver oxalate salts with higher solubility. When heated, it decomposes into silver metal, carbon monoxide, and carbon dioxide, making it an important precursor for producing high-purity silver powders used in electronics, thick-film pastes, and conductive inks.
- Synthetically, silver oxalate is typically prepared by precipitation: a soluble oxalate (such as potassium or sodium oxalate) is added to a soluble silver(I) salt (such as silver nitrate). The reaction produces a fine crystalline precipitate of Ag₂C₂O₄, which is washed and carefully dried. Its sensitivity to light and heat requires storing it in dark, cool conditions, usually in amber-colored containers.
- Because of its energetic decomposition, silver oxalate has been studied as a component in initiators, propellants, and gas-generating compositions, though these applications remain limited due to safety challenges. In analytical chemistry, it has occasionally been used in gravimetric methods for determining oxalate or silver content. Despite its hazards, it remains a compound of interest for materials science and energetic-material research due to its clean decomposition and ability to form controlled metallic silver structures.
