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