Question

What is the process of digestion, and why is it useful in the gravimetric determination of a precipitate?

Answer 1

Digestion is heating the solid and the mother liquor for a certain period of time. During this process small particles dissolve and large ones grow.
Gravimetric analysis requires particles large enough to be easily washed and filtered. That is why digestion process is a common component of the gravimetric determination of precipitate.