Grade 12 · Chemistry
The chemistry of buffers
Why it matters
Solutions that resist changes in pH.
Advanced20m readingPrerequisite: Hydrolysis of salts
What is a buffer solution?
Short answer
A buffer is a solution that resists changes in pH when small amounts of acid or base are added. It contains a weak acid and its conjugate base (or a weak base and its conjugate acid) in comparable amounts; one component neutralizes added base and the other neutralizes added acid. Buffers keep systems like blood at a nearly constant pH.
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Frequently asked questions
- How does a buffer resist pH change?
- Its weak-acid component neutralizes added base and its conjugate-base component neutralizes added acid, keeping [H⁺] nearly constant.
- Why is blood a buffered solution?
- The carbonic acid–bicarbonate buffer keeps blood pH near 7.4, which is essential for enzyme and cell function.