Question

A solution contains 0.5 moles of MgSO4 dissolved in 0.6 liters of water. In water MgSO4 dissociates into one Mg2 particle and one SO42- particle. What is the osmolarity of the solution?

Answer 1

Osmolarity = 1.66 Osm/L

Step-by-step explanation:

Osmolarity = Molarity . Number of ions dissolved.

MgSO₄ dissociates like this: MgSO₄ → Mg²⁺ + SO₄⁻²

Ions dissolved = 2

Let's determine molarity → mol/L → 0.5 mol/0.6L = 0.83M

Osmolarity is: M . 2 → 0.83M . 2 = 1.66 Osm

Note: when there is a solute which is non electrolyte, you don't have ions dissolved, so we consider: M = Osm