Key points are not available for this paper at this time.
One for all! On the basis of the absolute chemical potential of the proton, a unified absolute pH scale is introduced that is universally applicable in the gas phase, in solution, and in the solid state. With this scale, it is possible to directly compare acidities in different media, and to give a thermodynamically meaningful definition of superacidity. This scale can be used in all areas with variable proton activity.
Himmel et al. (Mon,) studied this question.