Cadmium iodide

Chemical properties

Pearly white flakes or a crystalline powder

Physical properties

White, hexagonal flakes or crystals; slowly turns yellow upon exposure to air or light; occurs in two allotropic forms, the alpha and beta forms; density 5.67 g/cm³; melts at 387°C (alpha form) and 404°C (beta form); vaporizes at 742°C; vapor pressures 1 and 5 torr at 416 and 481°C, respectively; soluble in water (86 g/100 mL at 25°C), ethanol, acetone, ether, and ammonia.

The Uses of Cadmium iodide

Cadmium iodide is used in lithography, photography, electroplating and the manufacturing of phosphors, in engraving process, and was used as an antiseptic and astringent.

The Uses of Cadmium iodide

Used in photography, analytical chemistry, manufacturing of phosphors, lubricants

The Uses of Cadmium iodide

In electrodeposition of Cd; as nematocide; in manufacture of phosphors; as lubricant; in photoconductors; in photography, process engraving; lithography; in analytical chemistry.

The Uses of Cadmium iodide

Made by the action of hydriodic acid on cadmium oxide and crystallization. The colorless, flaky crystals are soluble in water, alcohol, and ether. This halide was a common iodizer for collodion formulas, particularly for negatives.

Preparation

Cadmium iodide is prepared by the addition of cadmium metal, or its oxide, hydroxide, nitrate or carbonate to hydriodic acid:
CdO + 2HI → CdI₂ + H₂O
Also, the compound can be made by heating cadmium with iodine:
Cd +I₂ → CdI₂
A brownish crystalline β-form of the salt may be obtained by slow crystallization from solutions or fused salt mixtures.

Purification Methods

Crystallise it from ethanol (2mL/g) by partial evaporation. [Wagenknecht & Juza in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1096 1965.]