Understandings

Essential idea: The pH scale is an artificial scale used to distinguish between acid, neutral and basic/alkaline solutions.

pH = - log[H⁺(aq)] and [H⁺] = 10^-pH.

A change of one pH unit represents a 10-fold change in the hydrogen ion concentration [H⁺].

pH values distinguish between acidic, neutral and alkaline solutions.

The ionic product constant, Kw = [H⁺][OH^-] = 10^-14 at 298 K.

Applications and skills

Solving problems involving pH, [H⁺] and [OH^-].

Students should be familiar with the use of a pH meter and universal indicator.