Drying
The elimination of water or a solvent adhering to a surface or contained in a substance or a preparation. This operation can be carried out in special apparatus, e.g. drying ovens and desiccators, or can employ drying agents in a solution, e.g. anhydrous salts (MgSO4) for removing water.
Drying agent
A substance that can be used to remove residual amounts of water.
For example, finely powdered MgSO4 is suspended in an organic liquid containing traces of water.
CaCl2 and silica gel are used to remove water vapour from gases, e.g. in desiccators and guard tubes.
