Buffer Capacity and pH Calculations

🧪 Buffer Capacity & pH Calculations

📘 Henderson–Hasselbalch Equation:
pH = pKa + log([A⁻]/[HA])

🔁 Buffers resist pH change. Strongest when [A⁻] = [HA] → pH = pKa

🔥 What Affects Buffer Capacity?

• Higher concentrations = higher capacity
• Effective range is usually pKa ± 1
• Adding strong acid/base too fast = buffer overload

🧠 Quick Calculation

If pKa = 4.74 and [A⁻]/[HA] = 10, what’s the pH?

⚡ One Line Hack:

Equal amounts of acid and base → pH = pKa. That’s peak buffer power.

📊 Buffer Breakdown

If you add HCl to a buffer of acetic acid + sodium acetate, what happens to the pH?

✏️ Remember: Buffers are strongest at pH = pKa. Don’t let [A⁻]/[HA] ratios trick you!