Online pH calculator of Weak Acids

By using this online calculator, you can calculate pH and H+ concentration of weak acids such as acetic acid (CH3COOH), formic (HCOOH) and more. You have to choose the weak acid and give the concentration of acid.

pH calculator of aqueous weak acid solution

Ka values of weak acids are taken at 250C is taken. Also, assumed that, dissociation of water is negligible compared to dissociation of weak acids. If weak acid concentration is very much low such as 0.00000001 mol dm-3, pH value is approximately close to seven.


Calculation steps in this calculator

  • When pH value of dibasic weak acid is calculated, second dissociation is neglected because dissociation constant of second dissociation is less than dissociation constant of first dissociation.
  • Water dissociation is neglected because it is very weak than most of the weak acids.

Calculating pH of weak acid

Calculating pH of weak acid is not easy as calculating pH of strong acid. You need to know the dissociation constant of weak acid for calculation.