Lithium hydroxide (LiOH) is a corrosive alkali hydroxide. It is a white hygroscopic crystalline material. It is soluble in water, and slightly soluble in ethanol. It is available commercially in anhydrous form, or as the monohydrate.
Lithium hydroxide is used in carbon dioxide scrubbers
for purification of gases and air. It is used as a heat transfer medium, as a storage-battery electrolyte
, and as a catalyst
. It is also used in ceramics
, manufacturing other lithium compounds, and esterification
specially for lithium stearate
(which is used as a general purpose lubricating grease
due to its high resistance to water and is useful at both high and low temperatures).
Lithium hydroxide can be produced by dissolving lithium
or lithium oxide
. The reaction is as follows:
- 2 Li + 2 H2O → 2 LiOH + H2
- Li2O + H2O → 2 LiOH
is a strong base.
Because lithium reacts rapidly (but not violently) with water, lithium batteries should be kept away from water.
Industrially, lithium hydroxide is produced in a metathesis reaction between lithium carbonate and calcium hydroxide:
- Li2CO3 + Ca(OH)2 → 2LiOH + CaCO3
Lithium hydroxide is used in breathing gas
purification systems for spacecraft
(Lithium hydroxide canisters in the LM
(after modification) were lifelines for the Apollo 13
, and rebreathers
to remove carbon dioxide
from exhaled gas by producing lithium carbonate
- 2 LiOH·H2O + CO2 → Li2CO3 + 3 H2O
- 2LiOH + CO2 → Li2CO3 + H2O
The later, anhydrous hydroxide is preferred for its lower mass and lesser water production for respirator systems in spacecraft. 1 gram of anhydrous lithium hydroxide can remove 450 cm3 of carbon dioxide gas. The monohydrate loses its water at 100-110 °C.
LiOH(aq) + HF → LiF + H2O.
LiF shows basic nature, so it changes the red litmuspaper into blue.