Buffer Solutions
Testing pH Stability
Compare the pH stability of a buffer solution versus pure water when small amounts of acid or base are added. Observe how buffers resist pH changes while unbuffered solutions show large pH fluctuations.
pH 7.0
Buffer Solution
pH 7.0
Pure Water
Observation:
Click 'Add Acid' or 'Add Base' to observe pH changes. The buffer solution will resist pH changes while pure water will show significant changes.
pH Changes:
Buffer: pH 7.0
Water: pH 7.0
The Science Behind Buffer Solutions
Key Concepts:
Buffer solutions resist pH changes when small amounts of acid or base are added:
- Composition: Weak acid + its conjugate base OR weak base + its conjugate acid
- Buffer capacity: Amount of acid/base a buffer can neutralize before pH changes significantly
- pH calculation: Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA])
Buffer Action:
When acid is added, the conjugate base neutralizes it. When base is added, the weak acid neutralizes it. This maintains relatively constant pH.
Applications:
Used in biological systems (blood pH regulation), chemical processes, pharmaceuticals, and food preservation.
