What is the use of potassium bromide? What are the side effects of potassium bromide?

KBr 

Potassium bromide (KBr) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion (sodium bromide is equally effective). Potassium bromide is used as a veterinary drug, as an antiepileptic medication for dogs.

Under standard conditions, potassium bromide is a white crystalline powder. It is freely soluble in water; it is not soluble in acetonitrile. In a dilute aqueous solution, potassium bromide tastes sweet, at higher concentrations it tastes bitter, and tastes salty when the concentration is even higher. These effects are mainly due to the properties of the potassium ion—sodium bromide tastes salty at any concentration. In high concentration, potassium bromide strongly irritates the gastric mucous membrane, causing nausea and sometimes vomiting (a typical effect of all soluble potassium salts)

Potassium bromide is transparent from the near ultraviolet to long-wave infrared wavelengths (0.25-25 µm) and has no significant optical absorption lines in its high transmission region. It is used widely as infrared optical windows and components for general spectroscopy because of its wide spectral range. In infrared spectroscopy, samples are analyzed by grinding with powdered potassium bromide and pressing into a disc. Alternatively, samples may be analyzed as a liquid film (neat, as a solution, or in a mull with Nujol) between two polished potassium bromide discs.

Due to its high solubility and hygroscopic nature it must be kept in a dry environment. The refractive index is about 1.55 at 1.0 µm.

Formula: KBr
Molecular Weight: 119.002 g/mol
Form: powder
CAS Number: 7758-02-3
Density: 2.75 g/cm³
Synonyms: Kalii bromidum, Caswell No. 684, Kaliumbromid, Psorizide forte