The Kilcher Homestead is a 600 acre Pioneer Homestead that has been protected for perpetuity via a ConservatIon Easement. The Kilcher Family has also preserved the Historic Cabin and site as a LIving Museum.
Yes, negative pH is possible, but not in water as a solvent. The range of pH in water is 0 to 14 (to be more precise, it is -1.7 to 15.7, but for simplicity's sake, we start with the usual values.) Thus, what pH indicates is the ability of the acid to form H3O+, which can then donate a proton.
In the presence of a strong base, the -NH3+ end of the molecule loses an H+ ion to form a molecule with a net negative charge. The figure below shows what happens to the pH of an acidic solution of glycine when this amino acid is titrated with a strong base, such as NaOH. In order to understand this titration curve, let's start with the equation that describes the acid-dissociation equilibrium constant expression for an acid, HA.