Henderson-Hasselbalch Buffer Solution Calculator
Calculates buffer solution pH and required conjugate acid-base molar ratios using the Henderson-Hasselbalch equation, with presets for Phosphate, Acetate, TRIS, Carbonate, and HEPES buffers and buffering capacity (β) analysis.
Henderson-Hasselbalch Buffer Solution Calculator
Calculate buffer pH, conjugate acid-base molar ratio, and buffer capacity (β) against added strong acid or base
What is a Buffer Solution?
A chemical buffer is an aqueous solution consisting of a mixture of a weak acid and its conjugate base (or a weak base and its conjugate acid).
It resists drastic changes in pH upon the addition of small amounts of strong acid or base, making it critical for biochemical assays, cell cultures, and chemical syntheses.
Formula & Step-by-Step Calculation
Henderson-Hasselbalch relation for weak acid buffer systems and Van Slyke buffer capacity formula.
Worked Step-by-Step Examples
Calculate the pH of an acetate buffer with 0.15 M Acetate ([A⁻]) and 0.10 M Acetic Acid ([HA]), pKa = 4.76
Common Real-World & Academic Use Cases
- ✓ Preparing biological buffers (PBS, TRIS-HCl, HEPES) at physiological pH 7.4
- ✓ Formulating pharmaceutical injectable solutions
- ✓ Enzymatic assay optimal pH stabilization
- ✓ Analytical chromatography mobile phase preparation
How to Use the Henderson-Hasselbalch Buffer Solution Calculator
Select Buffer System or Preset
Choose Acetate (pKa 4.76), Phosphate (pKa 7.20), TRIS (pKa 8.06), Carbonate, or enter custom pKa.
Enter Concentrations or Target pH
Specify conjugate base [A⁻] and acid [HA] concentrations, or enter desired target pH to calculate required ratio.
Simulate Acid/Base Addition
Optionally test how adding strong HCl or NaOH shifts the buffer pH and inspect buffering capacity β.
Frequently Asked Questions
Q: What is the optimal pH buffering range of a buffer?
A buffer works most effectively within ±1 pH unit of its weak acid's pKa (pH = pKa ± 1). At pH = pKa, [A⁻] = [HA] and buffer capacity is at its theoretical maximum.