Practice question · Match the pairs
Match each titration pairing to the pH at its equivalence point.
- Strong acid with strong base
- Weak acid with strong base
- Strong acid with weak base
- Half-equivalence of a weak acid
- Equal to the acid pKa
- Below 7
- Exactly 7
- Above 7
Hints
- Ask which ion is left in solution once the reaction is complete.
- A leftover conjugate base raises the pH; a leftover conjugate acid lowers it.
Show the answer
- Strong acid with strong base → Exactly 7
- Weak acid with strong base → Above 7
- Strong acid with weak base → Below 7
- Half-equivalence of a weak acid → Equal to the acid pKa
Why
Only strong-with-strong leaves ions that do not hydrolyse, giving a neutral 7. A weak parent on either side leaves a hydrolysing conjugate that pushes the equivalence pH away from neutral.
Practise Buffers, Hydrolysis and Titration
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