[Chemistry Class Notes] Lithium Bromide Pdf for Exam

Lithium bromide is an ionic compound of lithium and bromine. Lithium is an alkali metal that has 3 electrons. The electronic configuration of lithium is 2,1. Thus, it has 1 electron in its valence shell. On the other hand, bromine is a non – metal that has 35 electrons in its single atom. Its electronic configuration is 2,8,18,7. Thus, it has 7 electrons in its valence shell. Lithium can attain electronic configuration like nearest noble gas He by donating one electron while bromine can attain electronic configuration like nearest noble gas Kr by accepting one electron. So, Li donates one electron to bromine and forms an ionic bond. Thus, both the elements get stability by attaining electronic configuration like nearest noble gas and form a new compound LiBr. 

An Interesting Salt Lithium Bromide (LiBr)

Lithium (Li) is the 3rd element in a series of elements as mentioned in a periodic table. It can chemically combine with the Bromine (Br)element to form a chemical compound called Lithium bromide (Libr). It is a type of salt as sodium chloride (NaCl) but what differs it from other salts is that it is extremely hygroscopic in nature. This property of Lithium bromide makes it a very useful substance in various places. Though it is available naturally due to its large amount of use, it is now being produced artificially by industrial methods.  To produce Lithium bromide lithium carbonate and hydrobromic acid are used. Both the compounds are suspended in water to come closer and react. In this mechanism, Lithium Bromide precipitates down in that aqueous solution. 

The most popular use of Lithium bromide is its use in Air conditioning systems as a desiccant and rarely in absorption refrigerators as a heat-absorbing salt.  The other uses of Lithium bromide include its use as a catalyst for oxidation and hydroformylation of organic compounds or sometimes for their deprotonation and dehydration. In medical science, it is also used for the purification of various steroids that are used for treating ailments or suppressing pain. Lithium bromide is also infamous as a  sedative of the early 2oth century. So it can be said that Lithium bromide has some psychoactive properties. Another great use of Lithium bromide is that it is used as a drug to treat bipolar disorder.

Properties of Lithium Bromide 

Physical and chemical properties of lithium bromide are listed below –

• It is soluble in water. Its solubility in water increases, as the temperature increases. For example, its solubility in water is 143 g/100 ml at 0 oC and as the temperature reaches up to 20 oC, its solubility becomes 166.7 g/100ml. 

• It is also soluble in methanol, ethanol, ether, acetone etc. It is slightly soluble in pyridine. 

Cl2 + 2LiBr → Br2 + 2LiCl 

Structure of Lithium Bromide 

In lithium bromide, an ionic bond is formed by the transfer of an electron from lithium to bromine. As lithium donates an electron so it forms a cation or gets a positive charge Li+. While bromine accepts an electron, it forms an anion or gets a negative charge Br–. The crystal structure of lithium bromide is cubic.

Production of Lithium Bromide 

Lithium bromide can be prepared by many methods. A few of them are listed below –

Li2CO3 + 2HBr → 2LiBr + H2CO3

  LiOH + HBr → LiBr + H2O

Uses of Lithium Bromide 

Lithium bromide is used in many fields. A few of its uses are listed below –