Multiply the number of particles produced from dissolving the solution in water by the molarity to find the osmolarity (osmol). For instance, if your have a 1 mol solution of MgCl2: 1 x 3 = 3 osmol. Repeat multiplying the molarity by the number of particles for the other solution to find the osmolarity.

How do you calculate tonicity?

According to our students' reports, they found it helpful to remember that tonicity is defined by the effect a solution has on cell volume at equilibrium, and that tonicity is determined by comparing the concentrations of nonpenetrating solutes in the solution and the cell.

How do you calculate osmolarity of glucose?

The molecular weight of glucose is 180 g. Finally, we know that the sugar molecule remains intact and does not break into smaller bits, so 1 M = 1 OsM. Now that everything is in the right units, we just need to divide moles by litres to get the osmolarity: 0.15 mole / 0.25 litre = 0.60 OsM.