Hygroscopic

Name:
Hygroscopic
Detailed information:
Descriptive of a substance that has the property of adsorbing moisture from the air, such as silica gel, calcium chloride or zinc chloride. The water-vapor molecules are held by the molecules of the agent, which is called a desiccant when used primarily for this purpose. Paper and cotton fabrics are hygroscopic, normally containing 5–8% water after standing in an atmosphere of normal humidity; they are usually kept in constant-humidity rooms before use. Many dry chemicals are hygroscopic and should be kept in well-stoppered bottles or tightly closed containers.See Deliquescent.