silverhaliderna

Silverhaliderna is a family of chemical compounds with the general formula AgX, where Ag represents silver and X represents a halogen atom. The halogens are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Therefore, the common silver halides are silver fluoride (AgF), silver chloride (AgCl), silver bromide (AgBr), and silver iodide (AgI).

These compounds exhibit varying degrees of solubility in water. Silver fluoride is the most soluble, while silver chloride, silver bromide, and silver iodide are progressively less soluble, with silver iodide being practically insoluble. This difference in solubility is a key characteristic used in qualitative and quantitative chemical analysis. For example, the addition of silver nitrate solution to a solution containing halide ions will precipitate the corresponding silver halide, with the color and insolubility of the precipitate indicating the presence and identity of the halide.

Silver chloride, silver bromide, and silver iodide are all light-sensitive. When exposed to light, they undergo decomposition, forming metallic silver and releasing halogen molecules. This property is the basis for their historical use in photography. Silver bromide was particularly important, as it offered a good balance of light sensitivity and stability.

In terms of structure, solid silver halides are typically ionic compounds with crystal lattice structures. The specific crystal structure can vary depending on the halide ion. These compounds have various applications beyond photography, including in some types of electrodes and as antimicrobial agents, though their use in the latter context is often limited by their light sensitivity and staining properties.