# Surface tension of solutions and mixtures

The inspiration for this question is over on cooking.stackexchange, asking more about actual measurements for commonly consumed liquids, but I'm interested more generally as well.

What determines the behavior of surface tension for solutions and mixtures with respect to concentration? Of course, I expect that the answer depends on the liquid, since different liquids have different causes of cohesive forces. I would be interested both in quantitative answers (very approximate/general, probably) and qualitative ones.

Additionally, what is the dependence of surface tension on temperature? Does that have any interaction with dependence on solution/mixture concentration?

(I know this question borders on chemistry, but there's no chemistry stackexchange, and besides, I'm sure at least some surface tension properties admit explanations from statistical mechanics!)

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Surface tension is physics, so this is fine here. By the way, "dependence of surface temperature on temperature"? I'm guessing you meant to say something else there ;-) –  David Z Sep 7 '11 at 0:34
@David: Oops! And thanks; it's certainly physics in my book but I figured once you start venturing into solutions, you sometimes get stuck with chemistry-style approximate relations based only on empirical evidence. (This seems especially possible given the sources of cohesive forces between more complex molecules.) –  Jefromi Sep 7 '11 at 2:51
If you want some pointers to some of the information about that topic that can be rigorously extracted in simple Ising-like systems, you can have a look at scholarpedia.org/article/Interface_free_energy . Of course, much more is known (in these "simple" models). –  Yvan Velenik May 25 '12 at 17:07