Chemistry

Colligative Properties (continued)


Ionic solutions

These are solutions that have ions as dispersed particles. In an ionic solution, not all ions are dissociated, ie not all ions are dissolved in the solution.

In order to calculate the dissociated particles in ionic solutions, it is necessary to take into account the degree of dissociation or ionization () of the substance that is dissolved.

The ionic particles may be acids, bases or salts.

If sulfuric acid has an ionization degree of 61%, this means that 61% of its ions dissociate and 39% do not dissociate.

Example: Consider that an Al solution2(ONLY4)3 is dissolved in water and its dissociation is 100%

If you had 60% dissociation degree:

In 1 mol of dissolved particles:
- 0.6mol of ionized particles
- 0.4mol of nonionized particles

Formula for ionized particles:

Formula for non-ionized particles:

Where:
n1 = mol number of solute
degree of dissociation (%)
# ions = number of ions in solution

Here's how the calculation can be done:

Calculate the number of particles dissolved in a solution containing 33g of H3PO2 with :

1 °) assemble the dissociation reaction:

2 °) calculate the molar mass:

MM = molar mass (H3POWDER2) = 66g / mol

3 °) Calculate the number of mol:

4 °) Calculate the number of ionized and non-ionized particles, then add:


Note that the degree of ionization in the formula has been divided by 100.