1. What is the Henderson-Hasselbalch Equation?

The Henderson-Hasselbalch equation relates the pH of a buffer solution to the pKa of the acid and the concentrations of the acid and its conjugate base. It's fundamental in chemistry and biochemistry for preparing buffer solutions.

2. How Does the Calculator Work?

The calculator uses the Henderson-Hasselbalch equation:

Where:

• \( pH \) — The calculated pH of the buffer solution
• \( pKa \) — The acid dissociation constant of the weak acid
• \( [base] \) — Concentration of the conjugate base (mol/L)
• \( [acid] \) — Concentration of the weak acid (mol/L)

Explanation: The equation shows that buffer pH depends on the ratio of base to acid concentrations, not their absolute values.

3. Importance of Buffer pH Calculation

Details: Buffer solutions resist pH changes when small amounts of acid or base are added. Accurate pH calculation is crucial for biological systems, chemical experiments, and industrial processes where stable pH is required.

4. Using the Calculator

Tips: Enter pKa value (typically between 0-14), base and acid concentrations in mol/L. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the effective buffer range?
A: A buffer is most effective when pH = pKa ± 1, where the ratio [base]/[acid] is between 0.1 and 10.

Q2: Can I use this for strong acids/bases?
A: No, this equation only applies to weak acid/conjugate base pairs. Strong acids/bases completely dissociate.

Q3: What if my acid and base concentrations are equal?
A: When [base] = [acid], the log term becomes zero and pH = pKa.

Q4: How does temperature affect the calculation?
A: pKa values are temperature-dependent. Use the pKa value appropriate for your experimental temperature.

Q5: What are common buffer systems?
A: Common systems include acetic acid/acetate (pKa 4.76), phosphate (pKa 7.21), and Tris (pKa 8.07).