Acid strength versus concentration

Acid strength describes the extent of proton donation in a specified solvent. Concentration describes how much acid is present per solution volume. A strong acid can be dilute, and a weak acid can be concentrated. These are different properties. For otherwise comparable weak acids in water, a larger acid dissociation constant indicates stronger proton donation. The pH still depends on concentration as well as acid strength. Do not rank solution acidity from the label weak or strong alone.