When crystallizing, why does a low yield of crystals result when too much solvent is added?

Question

I recently learned that when crystallizing something such as sulfanilamide, adding too much solvent (such as ethanol) results in little to no yield of purified crystals. Why does this occur?

Answer 1

Your solid crystallises because there is too much in the solution. The more solvent you have, the more of your product will stay in solution.
When you evaporate a liquid from a solution, you will always have a little bit of your solid still in the liquid when it evaporates. This means the more liquid you need to get rid of, the more of your solid you will lose.

Answer 2

Beacuse a great deal of your product still remains in solution!