pH & Buffer Calculator

Compute pH, pOH, and percent ionization for strong acids/bases, weak acids/bases, and Henderson-Hasselbalch buffers.

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What This Calculator Does

This calculator covers the most common introductory acid-base cases: strong acids, strong bases, weak acids, weak bases, and buffer mixtures handled with the Henderson-Hasselbalch equation.

It combines Calculation Mode, Acid Concentration, Base Concentration, Ka to estimate pH, pOH, [H+].

Formula & Method

Core equations: mathrm{pH}=-log_{10}[H^+], mathrm{pOH}=-log_{10}[OH^-], and for a buffer mathrm{pH}=pK_a+log_{10}left(rac{[A^-]}{[HA]} ight).

Notation used in the formulas: R = pH; x_{1} = Calculation Mode; x_{2} = Acid Concentration; x_{3} = Base Concentration; x_{4} = Ka; x_{5} = Kb; x_{6} = [HA] for Buffer.

Method summary: inputs are normalized to consistent units, core equations are evaluated, then secondary values are derived and rounded for display.

Use it when comparing simple acid-base scenarios or estimating the pH shift produced by changing acid and conjugate-base concentrations.

Inputs Used

Calculation Mode: Used directly in the calculation.
Acid Concentration: Used directly in the calculation.
Base Concentration: Used directly in the calculation.
Ka: Used directly in the calculation.
Kb: Used directly in the calculation.
[HA] for Buffer: Used directly in the calculation.
[A-] or [BH+] for Buffer: Used directly in the calculation.

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