How to use the activity coefficient calculator
Estimate the activity coefficient of an ion in solution from its charge and the ionic strength. Enter ion charge, ionic strength in the fields above; the activity coefficient (limiting law), activity coefficient (extended law) are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “activity coefficient”, “Debye Huckel”, “ion activity correction”, “calculate activity coefficient”, “find activity coefficient”.
Formula
Variables
- z — Ion charge
- I — Ionic strength (M)
Worked example
With ion charge = 2, ionic strength = 0.01 M, the calculator gives activity coefficient (limiting law) ≈ 0.6257488; activity coefficient (extended law) ≈ 0.6529938.
Frequently asked questions
What is the activity coefficient calculator used for?
Estimate the activity coefficient of an ion in solution from its charge and the ionic strength. It helps with questions such as “activity coefficient”, “Debye Huckel”, “ion activity correction”.
What is the formula for the activity coefficient calculation?
Activity coefficient (limiting law) = 10^(-0.509 × z × z × √(I)). Activity coefficient (extended law) = 10^(-0.509 × z × z × √(I) / (1+√(I))). Here z is ion charge, I is ionic strength (M).
What inputs do I need for the activity coefficient calculator (debye-hückel) calculator?
You need ion charge, ionic strength in M. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the activity coefficient calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the activity coefficient result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.