Sodium bromide is a
salt with the
formula NaBr,
widely used as an anticonvulsant and a
sedative in the
late 19th and early 20th centuries. Its action is due to the bromide ion (potassium
bromide is equally effective). It is a high-melting white, crystalline
solid that resembles sodium chloride. It is a widely used source of the bromide ion.
Principal chemical reactions
NaBr is widely used in
organic synthesis
as a nucleophile
to convert organochlorine
compounds to organobromine derivatives, which are more usefully (selectively)
reactive.
NaBr + RCl → RBr + NaCl
Sodium bromide can be used as a source of
the chemical element
bromine. This can
be accomplished by bubbling
chlorine gas
through an aqueous solution of NaBr.
As a source of HBr, NaBr is treated with a
strong, non-volatile acid:
NaBr + H3PO4 → HBr + NaH2PO4
HBr can also be oxidized to Br2 using MnO2
or concentrated H2SO4.
Other applications
Used as a
hypnotic,
anticonvulsant,
and sedative in
medicine. As a
source of the bromide ion, which is pharmacologically active, it is equivalent
to potassium bromide
(see this article for more complete discussion of this topic).
In
photography
Used to establish a
bromide
ion reserve in a
bromine spa (hot
tub) antimicrobial treatment regimen.