Silver, Citrate of. (See [Citric Acid.])
Silver, Iodide of.
Symbol, AgI. Atomic weight, 234.
Preparation and Properties of Iodide of Silver.—Iodide of silver may be formed in an analogous manner to the chloride, viz. by the direct action of the vapor of iodine upon metallic silver, or by double decomposition between solutions of iodide of potassium and nitrate of silver.
When prepared by the latter mode it forms an impalpable powder, the color of which varies slightly with the manner of precipitation. If the iodide of potassium be in excess, the iodide of silver falls to the bottom of the vessel nearly white; but with an excess of nitrate of silver it is of a straw-yellow tint. This point may be noticed, because the yellow salt is the one adapted for photographic use, the other being insensible to the influence of light.
Iodide of silver is tasteless and inodorous; insoluble in water and in dilute nitric acid. It is scarcely dissolved by ammonia, which serves to distinguish it from the chloride of silver, freely soluble in that liquid. Hyposulphite of soda and cyanide of potassium both dissolve iodide of silver; it is also soluble in solutions of the alkaline bromides and iodides.
Silver, Fluoride of.
Symbol, AgF. Atomic weight, 127.
This compound differs from those just described in being soluble in water. The dry salt fuses on being heated, and is reduced by a higher temperature, or by exposure to light.
Silver, Sulphuret of.