Theory 22/Solvation & interfaces/Surface tension
Salt Raises Tension by Depletion
The claim
The surface tension of an electrolyte rises with the ratio of ion depletion at the interface to bulk concentration, because ions are excluded from the surface layer.
01Mechanism
A depleted layer has higher effective surface energy.
02Prediction
Rise should track the depletion ratio.
03Refutation
Tension tracking concentration alone would remove the depletion.