Ionic Strength and Activity Calculator
Calculate ionic strength from an ion list and limiting Debye–Hückel activity coefficients at a supplied A constant.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Sum all entered charged species on the molarity convention and evaluate the dilute limiting law.
I=½Σci zi²; log10 γi=−A zi²√I
Worked example
For 0.001 M monovalent cations and 0.001 M monovalent anions, ionic strength is 0.001 mol/L.
Assumptions and input details
Matching nonnegative concentrations and integer charges |z|≤10. Scoped to I≤0.01 mol/L for this limiting-law approximation; no extended Debye–Hückel/Davies fitting. A must match solvent/temperature. A nonzero listed charge sum flags incomplete/nonneutral input; no balancing ions are invented.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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