Can the pH scale be utilized for all acids (Arrhenius, Bronsted-Lowry, and Lewis)? Give examples of substances from each definition category that can/cannot use the pH scale and explain your reasoning.

No

Explanation:

The pH scale is a scale graduated from 0-14 which shows the degree of acidity of alkalinity of a substance. The pH scale is graduated in such a way that 0-6.9 indicates acidity, 7.0 indicate a neutral substance, while a pH of 8-14 indicates alkalinity respectively.

There are three main definitions of acids/bases

- Arrhenius definition

-Brownstead-Lowry definition

-Lewis definition

Arrhenius explains acids as any substance that produces hydrogen ions as its only positive ion in solution while a base produces hydroxide ions as its only negative ion in solution. The pH scale is based on corresponding values of pH derived from aqueous solutions of these substances.

However, not all acids/bases produces hydrogen or hydroxide ions in solution. Brownstead-Lowry definition of acids and Lewis definition of acids could be extended to nonaqueous media where the pH can not be measured as there are no hydrogen or hydroxide ions present in the solution.

This implies that pH measurement may not apply to acids/bases in the all the categories of acids/bases hence it can not be utilized for all acids and bases.

Arrhenius - sodium carbonate

Brownstead-Lowry - concentrated HF

Lewis acid - AlCl3