Hullo. I'm doing a lab report on boiling point elevation, and we have to answer the question: "the boiling point elevation is higher than the calculated value, Why?". as a question on the side. In the experiment, the solution is 30g/l NaCl in water. The equation used to calculate the calculated value is Boiling point elevation = Molal elevation const. x Molality. Molal elevation const = 0.52 I'm looking for some kind of molecular description, I thought it might be to do with breaking ligand bonds between the water and the salt during evapouration, but dissolving NaCl is endothermic (according to wikipedia~~~), plus i don't think it would have that effect until you boil it dry. I know the equation assumes it's an ideal solution, and it's not cos NaCl is ionic, what can't explain is why the boiling point elevation would be more than the calculated value, rather than just different from it... any help greatly apprecaited, thanks.