# Ionic Force

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

Calculator of the ionic force of an aqueous solution.

Enter data separated by a space.

Powers of 10 : input **2.5*10^-3** or **2.5e-3** for `2.5*10^(-3)`.

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 Na^{2}SO^{4}and 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 (Na^{2}SO^{4}) = 142 g/mol

Molar mass potassium chloride (KCl) = 74.5 g/mol

Molar concentrations:

С (Na^{2}SO^{4}) = 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^{+}] * 1^{2}+ 1 * [SO4^{2-}] * 2^{2}+ 1 * [K^{+}] * 1^{2}+ 1 * [Cl^{-}] * 1^{2})

I= 0.5* (2 * 0.3 * 1^{2} + 1 * 0.3 * 2^{2} + 1 * 0.4 * 1^{2} + 1 * 0.4 * 1^{2} )

The corresponding calculator: I = 1.3 M

## See also

Conversion of molar concentration units

Molar concentration calculator

Solution and Equilibrium Calculators

Chemistry Calculators