(Redirected from Bromides)
A 'bromide'
ion is a
bromine atom with
charge of −1.
Compounds with bromine in formal
oxidation state −1 are called 'bromides'. This can include
ionic compounds such as
caesium bromide or
covalent compounds such as
sulfur dibromide.
Bromide compounds, especially
potassium bromide, were frequently used as sedatives in the 19th and early 20th century. This gave the word "bromide" its colloquial connotation of a boring
cliché, a bit of
conventional wisdom overused as a sedative.
One can test for a bromide ion by adding dilute
nitric acid (HNO
3), then
silver nitrate (AgNO
3). A cream precipitate forms that disappears in concentrated
ammonia solution.
Bromide is present in typical
seawater (35
PSU) with a concentration of aroud 65 mg/l, which is around 0.2% of all dissolved
salts.
Bromide is needed by
eosinophils (white blood cells of the granulocyte class, specialised for dealing with multicellular parasites), which use it to generate antiparasitic brominating compounds by the action of esoinophil
peroxidase, an enzyme which preferentially uses bromide.
[1]. Bromide is also used in
hot tubs and spas as a germicidal agent, using the action of an oxidizing agent to generate
hypobromite in a similar fashion to the peroxidase in eosinophils.
In some cases, bromide is available in a liquid form at pharmacies. It has been rumoured that bromide can reduce incidence of erections for males (see
anaphrodisiac), and this was actually its initial pharmacological use. However, such an action is common to all effective sedatives and not known to be especially particular to bromide.
Examples
★
hydrogen bromide (HBr)
★
sodium bromide (NaBr)
★
potassium bromide (KBr), once a commonly used sedative
★
carbon tetrabromide (CBr
4)
★
sulfur dibromide (SBr
2)
See for a bigger list.
External links