The experimental boiling point of the NaCl solution is lower than that calculated, assuming that NaCl is completely dissociated in solution. Why is this the case? I'm thinking that this is because some of the Na+ and Cl- ions reassociate for a short time, thus causing the solution to contain somewhat less than two times the original concentration of NaCl. The phrase in the question "assuming that NaCl is completely dissociated in solution." is making me doubt this answer. Does anyone have any suggestions?