Solutions of hydrochloric acid and ethanoic acid have the same concentration. The hydrochloric acid has the lower pH. Why?
Answer and explanation
Correct answer: C. Hydrochloric acid is a strong acid and fully ionises
- Step 1: A strong acid ionises completely, so more hydrogen ions are present.
- Step 2: A weak acid ionises partly, so its pH is higher.
Answer
Hydrochloric acid is a strong acid and fully ionises.
Why not the others: Ethanoic acid is a base: it is an acid. Hydrochloric acid has a lower concentration: the concentrations are equal. Ethanoic acid does not contain hydrogen: it contains hydrogen.
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