Lithium bromide

lithium bromide LiBr, the lithium salt of the hydrobromic acid, forms colorless, strongly hygroscopic crystals with a melting point of 550°C, a boiling point of 1265°C and a density of 3,46 g/cm ³. The molecular mass of water-protected lithium bromide amounts to 86.85 g/mol. The Lösungswärme amounts to2,7 kJ/mol.

Beside water-free lithium bromide still different hydrates exist, admit are LiBr · n H 2 O with n= 1, 2, 3 and 5. Mono hydrate LiBr · H 2 O points a density from 2,51 g · cm-3 up.

production

the production of lithium bromide takes place via conversion aqueous lithium hydroxide - or lithium carbonate solution with Bromwasserstoff and following concentration and drying process.

LiOH + HBr → LiBr + H 2 O
left 2 CO 3 +2 HBr → 2 LiBr + H 2 CO 3

water-free lithium bromide can be manufactured also by reaction by Lithiumhydrid with bromine.

+ if Br borrowed 2 → LiBr + to HBr

characteristics

lithium bromide is very hygroscopic, concentratedSolutions with 50% LiBr reduce the steam pressure of the water over approx. 80%. It is very well soluble in water, with 20°C is 60%ige solutions producible. Also in alcohol and glycol it is well soluble.

use:

  • AsSolution of lithium bromide in water for absorption refrigerators (> 50% of manufactured lithium bromide).
  • Because of the strongly hygroscopic effect as drying agents, also for dehumidifying closed areas.
  • Organic syntheses. As catalyst and Edukt.
  • Fluxing agent when soldering.
  • As electrolyte in some lithium battery types.
 

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