basic

Conjugate Base pH from pKa and Concentration Calculator

pH = 7 + ½(pKa + log C) — basic salt solution.

Calculates the pH of a conjugate base (A⁻) solution: pH = ½(pKw + pKa + log[C]), where pKw = 14. Accounts for hydrolysis: A⁻ + H₂O ⇌ HA + OH⁻.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

mol/L

Results

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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

pH = ½(pKw + pKa + log[A⁻]₀)

In depth

Calculates the pH of a conjugate base (A⁻) solution: pH = ½(pKw + pKa + log[C]), where pKw = 14. Accounts for hydrolysis: A⁻ + H₂O ⇌ HA + OH⁻.