1. What is Buffer Capacity?

Buffer capacity (β) measures how well a solution resists changes in pH when acid or base is added. It's defined as the amount of strong acid or base required to change the pH of 1 liter of solution by 1 unit.

2. How Does the Calculator Work?

The calculator uses the buffer capacity equation:

Where:

• \( \beta \) — Buffer capacity (mol/L pH)
• \( C \) — Total buffer concentration (mol/L)
• \( [A^-] \) — Concentration of conjugate base (mol/L)
• \( \alpha \) — Fraction of buffer in conjugate base form

Explanation: The equation shows buffer capacity depends on both the total buffer concentration and the ratio of conjugate base to weak acid.

3. Importance of Buffer Capacity

Details: Understanding buffer capacity is crucial in biochemistry, pharmaceutical formulations, chemical processes, and maintaining physiological pH in biological systems.

4. Using the Calculator

Tips: Enter total buffer concentration and conjugate base concentration in mol/L. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the maximum possible buffer capacity?
A: Maximum buffer capacity occurs when α = 0.5 (pH = pKa), where β = 0.576 × C.

Q2: How does buffer capacity change with pH?
A: Buffer capacity is highest near the pKa of the buffer system and decreases as pH moves away from pKa.

Q3: What are typical buffer capacity values?
A: Common biological buffers have capacities of 0.01-0.1 mol/L pH. Blood has β ≈ 0.03 mol/L pH.

Q4: Can this calculator be used for polyprotic buffers?
A: No, this equation is for monoprotic buffers. Polyprotic buffers require more complex calculations.

Q5: How does temperature affect buffer capacity?
A: Temperature mainly affects pKa values, which indirectly affects buffer capacity by changing α.