The salt is a typical ionic compound, although the small
size of the Li+ ion gives rise to properties not seen for other alkali metal
chlorides, such as its hygroscopic properties. The salt forms crystalline
hydrates, unlike the other alkali metal chlorides. Molten LiCl and LiCl-based
mixtures react under a humid atmosphere to form lithium hydroxide and hydrogen
chloride. Lithium chloride is used as a relative humidity standard in the
calibration of hygrometers. Additionally, lithium chloride can itself be used
as a hygrometer. The lithium chloride dew point hygrometer has many advantages over other types of hygrometers. However, it only reads and controls the dew point temperature of air instead of the relative humidity which is more important in the agriculture, food storage and hygiene.