Lithium hydroxide is an inorganic compound with the formula LiOH. It is a white hygroscopic crystalline material. It is soluble in water and slightly soluble in ethanol, and is the weakest base among the alkali metal hydroxides. 

 

It is available commercially inanhydrous form and as the monohydrate (LiOH.H2O), both of which are strong bases. Lithium hydroxide is produced in a metathesis reaction between lithium carbonate and calcium hydroxide.

 

Li2CO3 + Ca(OH)2 → 2 LiOH + CaCO3

 

The initially produced hydrate is dehydrated by heating under vacuum up to 180 °C.

 

In the laboratory, lithium hydroxide arises by the action of water on lithium or lithium oxide. The equations for these processes follow:

2 Li + 2 H2O → 2 LiOH + H2

Li2O + H2O → 2 LiOH

 

Typically, these reactions are avoided.

 

Although lithium carbonate is more widely used, the hydroxide is an effective precursor to lithium salts, e.g. LiOH + HF → LiF + H2O