Ionic Force

`I = 1/2 * \sum_{i} C_i * z_i^2 `
Calculator of the ionic force of an aqueous solution.
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Powers of 10 : input 2.5*10^-3 or 2.5e-3 for `2.5*10^(-3)`.

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This tool calculates the ionic force of an aqueous solution containing n ions. The formula of ionic force is as follows,

`I = 1/2 * \sum_{i=1}^n C_i * z_i^2`

i : the solution contains n ions and i refers to i-th ion of the solution so i = 1, 2 .... , n I : Ionic force of the solution in mol per litre.
C_i : molar concentration of i-th ion in mol per litre.
z_i : electronic charge of i-th ion (dimensionless).

Ionic force measures the concentration of the solution in ions and quantifies the interactions between ions and solvent and between ions.

Example of ionic force calculation

Example 1

How to calculate the ionic force of a solution of 1 liter NaCl sodium chloride at 0.02 M ?

We apply the above formula,

[Na⁺] = 0.02 M and [Cl^-] = 0.02 M

I = 0.5* [0.02 * (+1)² + 0.02 * (−1)² ] = 0.02 M

Here's the corresponding calculator: I = 0.02 M

Example 2
Let us calculate the ionic force of a 1-liter solution with 42.6 g sodium sulfate Na²SO⁴and 29.8 g potassium chloride KCl.

In order to apply the above formula, we need to calculate molar masses and molar concentrations.

Molar masses:
Molar mass sodium sulfate (Na²SO⁴) = 142 g/mol
Molar mass potassium chloride (KCl) = 74.5 g/mol

Molar concentrations:
С (Na²SO⁴) = 42.6/142 = 0.3 М
С (KCl) = 29.8/74.5 = 0.4 M

Finally, we can calculate the ionic force:
I= 0.5* (2* [Na⁺] * 1²+ 1 * [SO4^2-] * 2²+ 1 * [K⁺] * 1²+ 1 * [Cl^-] * 1²)
I= 0.5* (2 * 0.3 * 1² + 1 * 0.3 * 2² + 1 * 0.4 * 1² + 1 * 0.4 * 1² )

The corresponding calculator: I = 1.3 M

Ionic Force

Example of ionic force calculation

See also