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How does a liquid's vapour pressure affect its surface tension?
i.e. to say, if a liquid's vapour pressure increases, will the surface tension increase or decrease?
The SERP for this question yields only research papers to which I don't have access. This theory isn't given in my textbook either.
High surface tension is caused by strong intermolecular forces, the same are responsible for a low vapour pressure.
It is however quite a different matter to put a molecule on a surface and to completely strip it from a condensed phase and put it into the gas phase. There sure is no (inverse) proportionality or similar between vapour pressure and surface tension, and they don't "affect" each other.
A really stupid test question, imo.
When another independent variable such as temperature is applied, vapor pressure would increase due to weakening of the intermolecular forces; surface tension would decrease thus allowing more molecules to escape and so the solubility would decrease. However, the mass transfer rate would increase at a fixed dissolved gas concentration. The temperature imparts kinetic energy to the liquid so the molecules are more agitated. These are the effects of temperature on both parameters. I agree with the premise that vapor pressure and surface tension do not affect each other.
