pH Calculator for Acids

pH Calculator for Acids

Calculate the pH of a solution for both strong acids (complete dissociation) and weak (monoprotic) acids.

* Enter the acid concentration (M) and, for weak acids, its pKa value.

Step 1: Enter Parameters

Example: 0.10 M

Derived Formulas:
Strong Acid: \( \text{pH} = -\log_{10}[c] \)
Weak Acid: \( K_a = \frac{x^2}{c – x} \) with \( x = \frac{-K_a + \sqrt{K_a^2+4K_ac}}{2} \) and \( \text{pH} = -\log_{10}(x) \)
Note: For weak acids, \( K_a = 10^{-\,\text{pKa}} \).


Example:
For a 0.10 M acetic acid solution with a pKa of 4.75, the calculator computes the pH.