It is also used as a drying agent in dessicators and to dry the air entering a water sensitive reaction. The drierite can be obtained in a dyed form. The dye functions as an indicator of how much water has been absorbed. The dyed form is not suitable for use as a drying agent for liquids. Calcium chloride is very much like calcium sulfate except that it will also absorb methanol and ethanol.
Potassium carbonate is basic and as such, is generally used in basic media.
It is of average capacity, completeness and rate. At this point it is important to reiterate that when you add a drying agent to a solution, it will just sit on the bottom of the container because it is an insoluble solid. The problem with drying agents is there is a tendency to add to much. It is best to start conservatively. Add a spatula tip and then swirl.