Why does depression of freezing point takes place if a non-volatile solute is added to the solution?

Depression of freezing point


A simple "intuitive" oversimplification: intrusive foreign molecules get caught between solvent molecules, getting in the way of crystallization. That, however, would contradict the similar boiling point elevation.

Another oversimplification: the solute molecules pull the solvent away from the incipient crystals.

Yet another simplistic answer: osmosis exerts a force on the solvent, pulling it back into solution, away from the pure crystal of solvent.

Perhaps the last explanation is closest to a statistical analysis of freezing point depression.

Hopefully, chemistry will not be a depressing subject.

| improve this answer | |
  • $\begingroup$ osmosis is also a colligative property, but then both are not very well intuitively understandable. ;-) $\endgroup$ – Karl Nov 28 '18 at 2:06

Not the answer you're looking for? Browse other questions tagged or ask your own question.