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.
Battery acid is ranked as one of the most acidic substances because is has a pH value of zero. Concentrated sulfuric acid is also very acidic, being listed as one. Lemon juice and vinegar are also very acidic, but not as much so since they are ranked at a level two pH rating. Some other acidic substances are orange juice and soda, which have a pH rating of three.