AP Chemistry / Unit 8: Acids and Bases
8.8 Properties of Buffers
Notes
A buffer's pH depends on the ratio $\displaystyle \frac{[A^-]}{[HA]}$. It works best when $pH\approx pK_a$ (ratio near 1).
- Diluting a buffer doesn't change its pH much.
Practice
A buffer works best when the pH is near:
Equal amounts of HA and $\mathrm{A^-}$.
Diluting a buffer with water:
The ratio stays the same.
Adding a little strong acid to a buffer converts:
The base component reacts.
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