Page 42 - Curriculum Visions Dynamic Book

Bromine
Bromine, a dark red liquid, is named for the Greek word meaning “stench”. Bromine is never found as an element alone because, like the other elements in this book, it is very reactive. Bromine occurs as ions in sea water, and it is normally obtained as a byproduct of refining common salt.
Like iodine, bromine is concentrated in the bodies of some sea life. Both kelp and shellfish can be sources of bromine. The sea mollusc murex was traditionally used to make a purple dye, which was
a compound of bromine. People in the Victorian era drank a potion containing
a compound of bromine to help
them sleep.
Bromine is still used in dyes. It was used in leaded fuel, but this is declining with the use of unleaded fuels. It is perhaps best known for its use as silver bromide in photographic papers.
 Bromine gas.
Manufacturing bromine
Bromine can be made from sea water, using the property that chlorine will displace bromine in compounds.
About 22,000 tonnes of sea water have to be processed to collect one tonne of bromine.
EQUATION: Obtaining bromine from sea water
Chlorine gas + bromine ions in water ➪ bromine + chloride ions in water Cl2(g) + 2Br-(aq) ➪ Br2(g) + 2Cl-(aq)
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