Acid Dissociation Calculator
Calculate Ka for an acid.
About Acid Dissociation Calculator
For a weak acid, Acid Dissociation estimates the hydrogen-ion concentration from the dissociation constant and the acid's concentration, then converts it to pH. pH is a logarithmic scale, so each whole unit is a tenfold change in hydrogen-ion concentration.
Formula
Acid Dissociation
pH = -log10[H+], with [H+] = sqrt(Ka.C)
- Ka
- How readily the acid donates a proton
Worked example
With the default values below, Acid Dissociation Calculator returns pH of 2.872. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Acid concentrationminimum 0 M
- 0.1 M
- Acid dissociation constantminimum 0
- 0.000018
- Temperatureminimum 0 C
- 25 C
Results
- pH
- 2.872
- H+ Concentration
- 0.00134164 M
- Degree of Ionization
- 1.34%
Step by step
- 1Values used
- 2Acid Dissociation
- 3pH= 2.872
- 4H+ Concentration= 0.00134164 M
- 5Degree of Ionization= 1.34
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 8 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Acid Dissociation calculated?
pH = -log10[H+], with [H+] = sqrt(Ka.C) For a weak acid, Acid Dissociation estimates the hydrogen-ion concentration from the dissociation constant and the acid's concentration, then converts it to pH.
Why does Acid Dissociation matter?
pH is a logarithmic scale, so each whole unit is a tenfold change in hydrogen-ion concentration.
What values do I need to enter?
This calculator takes 3 inputs: Acid concentration, Acid dissociation constant, Temperature. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.