It is an example of physical change. The molecules are not changing, so it is not chemical, and a physical property is something that a physical thing has.
Answer:
The formula for calculating pH is pH=−log[H_3O+ ]
pH is the negative logarithm (to base 10) of hydronium ion concentration
The pH Formula can also be expressed as
PH= - log[H+ ]
Not sure but it might be A or B
