1. The problem statement, all variables and given/known data Why is the presence of undissolved solute necessary for the solution to be considered saturated? 2. Relevant equations N/A 3. The attempt at a solution Why can't there just be a saturated solution with no "excess" solute? For example, why can't there be a point od saturation where one more molecule would cause two molecules to bond and form the smallest "crystal" possible? Or am I just being too specific?