Description
Compare supplied Donnan concentration products.
Membrane electrical quantities distinguish total from area-specific properties, concentration ratios from activities and single-ion from multi-ion models. Local capacitance, current or potential terms require compatible sign, valence, temperature and unit conventions without themselves validating a biological membrane.
Compare supplied Donnan concentration products.
When to use this tool
Use Membrane Donnan Product Residual when evaluating the stated membrane, ionic or area-basis term.
How to use the tool and how it works
- Enter insideCation, insideAnion, outsideCation, outsideAnion. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read insideProduct, outsideProduct, residual. Use the output convention below.
Compare supplied Donnan concentration products. Require four nonnegative concentrations; return insideCation*insideAnion, outsideCation*outsideAnion and inside-minus-outside residual.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| insideCation | Inside Cation | Required. Finite number; minimum 0. |
| insideAnion | Inside Anion | Required. Finite number; minimum 0. |
| outsideCation | Outside Cation | Required. Finite number; minimum 0. |
| outsideAnion | Outside Anion | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| insideProduct | Inside Product | Required. Finite number. |
| outsideProduct | Outside Product | Required. Finite number. |
| residual | Signed difference in the direction stated above, with matching units. | Required. Finite number. |
{
"input": {
"insideCation": 2,
"insideAnion": 8,
"outsideCation": 4,
"outsideAnion": 4
},
"output": {
"insideProduct": 16,
"outsideProduct": 16,
"residual": 0
}
}Limitations and assumptions
- This checks one monovalent ideal-product relation only; charge balance, activities and actual equilibrium are not solved.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use verified concentrations, activities, geometry and electrical calibration with the appropriate complete membrane/channel model for physiological interpretation.
References
Similar or alternative tools
- Nernst Single Ion Gradient Term
Return a single-ion equilibrium potential.
- Ion Valence Potential Sign
Return electrostatic energy change and sign.