|MadSci Network: Chemistry|
This could be mainly semantics. In fact, if you read a physical chemsitry book you will find that pH can be classified as both. pH is in direct relationship to the Nernst Equation, which relates a chemical property such as the activity (or concentration in dilute solutions)of hydrogen ion to the chemical potential (electric) measured between a reference electrode and the glass electrode (Must pH (glass) electrodes have a built in refernece electrode). One can argue that the this electric potential (volts) is a physical property resulting from the transport of hydrogen ions from the outside solution (the solution you are measuring) into the solution inside the glass electrode.
I tend to treat pH as a physico-chemical property.
Hope this answer your question.
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