Calculadora de pH de Buffer — Fórmula

## Henderson-Hasselbalch Equation

### Formula

**pH = pKa + log₁₀([A⁻] / [HA])**

Where:
- **pH** = hydrogen ion activity
- **pKa** = acid dissociation constant (log scale)
- **[A⁻]** = concentration of conjugate base
- **[HA]** = concentration of weak acid

When [A⁻] = [HA], pH = pKa. Buffers resist pH changes best within ±1 of the pKa.

Ejemplo Resuelto

An acetate buffer with pKa = 4.76, [CH₃COO⁻] = 0.1 M, [CH₃COOH] = 0.1 M.

  1. pH = pKa + log₁₀([A⁻]/[HA])
  2. pH = 4.76 + log₁₀(0.1/0.1)
  3. pH = 4.76 + log₁₀(1)
  4. pH = 4.76 + 0
  5. pH = 4.76