Why is it important to maintain a minimal amount of boiling solvent during recrystallization?

Maintaining a minimal amount of boiling solvent during recrystallization is crucial to maximizing the yield of pure product. During this process, the solvent's purpose is to dissolve the solute at high temperatures, allowing impurities to remain in solution or to crystallize out as the solution cools. If there is too much solvent, the solute may not fully crystallize upon cooling, leading to a lower yield of the desired crystalline product.

Using just enough boiling solvent allows the maximum amount of the desired compound to dissolve while ensuring that as the solution cools, the conditions are optimal for crystal formation. A minimal solvent volume also enhances the likelihood that the forming crystals will be pure, as there is less solvent to interfere with the crystallization process. Overall, this approach helps achieve a higher yield of the pure compound desired from the recrystallization technique.