Calculadora de pH de Buffer Gratis
Calcula el pH de una solución amortiguadora usando la ecuación de Henderson-Hasselbalch.
M
M
Buffer pH
4.76
Base/Acid Ratio1.0000
Buffer pH vs pKa of Weak Acid
Fórmula
Henderson-Hasselbalch Equation
Formula
pH = pKa + log₁₀([A⁻] / [HA])
Where:
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.
- 01pH = pKa + log₁₀([A⁻]/[HA])
- 02pH = 4.76 + log₁₀(0.1/0.1)
- 03pH = 4.76 + log₁₀(1)
- 04pH = 4.76 + 0
- 05pH = 4.76
Preguntas Frecuentes
What is the Henderson-Hasselbalch equation?
It relates the pH of a buffer solution to the pKa of the acid and the ratio of conjugate base to acid concentrations. It is derived from the Ka expression by taking logarithms.
When is this equation most accurate?
It works best when the buffer ratio [A⁻]/[HA] is between 0.1 and 10, i.e., within ±1 pH unit of the pKa.
Can I use this for basic buffers?
Yes. Use pKa of the conjugate acid, [A⁻] as the base form, and [HA] as the acid form of the buffer pair.
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