"Hygroscopic" is a term describing a substance that, on standing, reacts with or absorbs
water vapor from the air. Magnesium chloride and concentrated sulfuric
acid are typical examples. Some hygroscopic solids such as magnesium
chloride, said to be deliquescent (see deliquescence),
absorb sufficient water to dissolve, yielding a concentrated solution.
|Magnesium chloride is both hygroscopic and deliquescent