Buffer
Definition
A buffer is a solution that resists changes in pH when small amounts of an acid or a base are added to it.
Analogy
Think of a buffer like the shock absorbers on your bike. Just as the shock absorbers help to smooth out your ride over bumps and dips, buffers in chemistry help to keep the pH level steady, even when acids or bases are added.
Related terms
Buffer Capacity: This refers to the amount of acid or base that can be added to a buffer without causing a significant change in pH.
Acidic Buffer: An acidic buffer is a type of buffer made from a weak acid and its salt (which will be composed of its conjugate base and a cation). It has a pH less than 7.
Basic Buffer: A basic buffer is made from a weak base and its salt (which will be composed of its conjugate acid and an anion). It has a pH greater than 7.
"Buffer" appears in:
Subjects (1)
Study guides (1)
Practice Questions (4)
- Which of the following is true about what occurs when an acid is added to a buffer?
- What amount of solid sodium acetate is needed to prepare a buffer of pH 5.0 from 1.00 L of 0.10 M acetic acid (pKa = 4.75; molar mass of sodium acetate = 80.0343 g/mol)?
- According to the Henderson-Hasselbalch equation, when the pH of a solution becomes equal to its pKa, the solution becomes a buffer. This condition is achieved when which of the following is true?
- We want to make a 100 mL buffer with a pH of 5. We are given 0.1 M each of HA and NaA. How many mL of each are required to make the buffer? (pKa = 4.7)
Resources
© 2024 Fiveable Inc. All rights reserved.
AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.