Most common drying agents
are anhydrous inorganic salts, e.g.,
anhyd. Na2SO4 or anhyd. MgSO4.
These solids are insoluble in organic solvents and remove
the water by forming hydrates.
- The drying agent is added to
the solution to be dried and left for about 10
min. When dry,
solutions usually are clear, not cloudy.
Hydrated inorganic salts are
usually unstable when heated, hence this process
should be carried out at room temperature. The
hydrates must be removed by filtration before a dried
solution is heated.
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