Cadmium bromide is a cream-coloured crystalline ionic cadmium

Cadmium

Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

 salt of hydrobromic acid

Hydrobromic acid

Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at 124.3 °C and contains 47.6% HBr by weight, which is 8.89 mol/L. Hydrobromic acid has a pKa of −9, making it a...

 that is soluble in water. It is very toxic, along with other cadmium compounds.

Uses

It is used in the manufacturing of photographic film

Photography

Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

, engraving

Engraving

Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

 and lithography

Lithography

Lithography is a method for printing using a stone or a metal plate with a completely smooth surface...

.

Preparation

Cadmium bromide is prepared by heating cadmium with bromine vapor. Also the compound can be prepared by the treatment of dry cadmium acetate

Cadmium acetate

Cadmium acetate is the chemical compound with the formula Cd2. This colourless solid is classified coordination polymer, featuring acetate ligands interconnecting cadmium centers. The compound exists in anhydrous form and as a dihydrate...

 with glacial acetic acid

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

 and acetyl bromide

Acetyl bromide

Acetyl bromide is an acyl bromide compound. As is expected, it may be prepared by reaction between phosphorus tribromide and acetic acid:...

. Alternatively, it can be obtained by dissolving cadmium or cadmium oxide

Cadmium oxide

Cadmium oxide is an inorganic compound with the formula CdO. It is one of the main precursors to other cadmium compounds. It crystallizes in a cubic rocksalt lattice like sodium chloride, with octahedral cation and anion centers. It occurs naturally as the rare mineral monteponite. Cadmium oxide...

 in hydrobromic acid

Hydrobromic acid

Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at 124.3 °C and contains 47.6% HBr by weight, which is 8.89 mol/L. Hydrobromic acid has a pKa of −9, making it a...

 and evaporating the solution to dryness under helium

Helium

Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

in an inert atmosphere.