Henderson-Hasselbalch Calculator
This calculator helps you determine the pH of a buffer solution using the Henderson-Hasselbalch equation. It is designed for chemistry students and professionals who need to solve buffer-related problems efficiently.
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Source of Data and Methodology
All calculations are based on the Henderson-Hasselbalch equation as detailed in authoritative chemistry resources. For more information, visit the MSD Manual.
The Formula Explained
\( \text{pH} = \text{pKa} + \log_{10} \left( \frac{[A^-]}{[HA]} \right) \)
Glossary of Variables
- pKa: The acid dissociation constant.
- [A-]: Concentration of the conjugate base.
- [HA]: Concentration of the acid.
How It Works: A Step-by-Step Example
For an acid with a pKa of 4.75, if the concentration of the base is 0.1 M and the acid is 0.01 M, the pH is calculated as follows:
\( \text{pH} = 4.75 + \log_{10} \left( \frac{0.1}{0.01} \right) = 5.75 \)
Frequently Asked Questions (FAQ)
What is the Henderson-Hasselbalch equation?
The Henderson-Hasselbalch equation is used to estimate the pH of a buffer solution using the pKa and the concentrations of an acid and its conjugate base.
What is a buffer solution?
A buffer solution is a system that maintains a relatively constant pH when small amounts of acid or base are added.
Why is pKa important?
pKa gives an indication of the strength of an acid; a lower pKa value indicates a stronger acid.
How does temperature affect the Henderson-Hasselbalch equation?
The pKa value can change with temperature, affecting the pH calculation.
Can this calculator be used for polyprotic acids?
This calculator works for monoprotic acids. For polyprotic acids, additional steps are required.