Potassium bromide  is white crystalline powder. Odourless. Salty, slightly bitter. Relative density 2.75; Melting point of 730; The boiling point of 1435 ºC. Soluble in water and glycerin, slightly soluble in ethanol and ether. Slightly hygroscopic. Turns yellow easily when exposed to light. Aqueous solution is neutral.

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Usage: This white crystal was made by the action on hot solution. It is soluble in water but much less so in alcohol. Potassium bromide was used as a secondary halide in combination with an iodide in the paper negative processes, the albumen on glass process, and the wet collodion processes. When silver bromide gelatin emulsion was invented, potassium bromide was the primary halide. It was also used in combination with either bichloride of copper sulfate, or potassium ferricyanide in photographic bleaches and as a restrainer in alkaline developers used for gelatin plates and developing-out papers.
Potassium bromide (KBr) is used in photography and as a medical sedative.
manufacture of photographic papers and plates; process engraving.