Appearance and Properties | white tetragonal crystal | molecular weight | 23.95 |
pH(1mol/L) | 14 | Solubility | Soluble in water, slightly soluble in ethanol |
Melting point(℃) | 471.2 | Relative density (water=1) | 1.46(anhydrous) |
1.51(monohydrate) | |||
Molecular formula | LiOH |
Chemical properties
It is easy to absorb carbon dioxide and moisture in the air, but the absorption capacity is slightly worse than that ofNaOHandKOH.Lithium hydroxide has the general property of alkali, and the following reactions can occur.
1.alkaline reaction
It can make purple litmus test solution blue and colorless phenolphthalein to turn red; and its concentrated solution can denature phenolphthalein after experimental verification, so that the solution changes from red to colorless (similar to concentratedNaOH).
2.neutralized with acid
HCl+LiOH=LiCl+H2O
3.Reacts with acidic oxides
2LiOH+CO2=Li2CO3+H2O(this reaction is used to absorb carbon dioxide in aerospace)
4.Reacts with metal salt solutions
FeCl3+3LiOH=Fe(OH)3↓+3LiCl
Use
Lithium hydroxide can be used as developing agent and lubricating oil for spectral analysis.The additive of alkaline battery electrolyte can increase the electric capacity by12%to15%and increase the service life by2to3times.
It can be used as an absorbent for carbon dioxide and can purify the air in submarines.
The chemical equation is:2LiOH(s)+CO2(g)=Li2CO3(s)+H2O(l).
It is used to make lithium salt and lithium-based grease, electrolyte of alkaline battery, absorption liquid of lithium bromide refrigerator, etc.;used in petroleum, chemical industry, light industry, nuclear industry, etc.When used in alkaline batteries, the aluminum content is not more than0.06%, and the lead content is not more than0.01%.It is used as an analytical reagent, a photographic developer, and also in the manufacture of lithium;it is used as a raw material for the preparation of lithium compounds.It can also be used in metallurgy, petroleum, glass, ceramics and other industries.