How are molarity and osmolarity different? what property of salts necessitates this distinction? how does this property affect the behavior of water?

Explanation:

The number of moles that are present in a liter of a solution is called Molarity. Mole is the unit of Molarity.The concentration of the solutes that are present in a solution refers to Osmolarity . The unit is osmol. This helps in observing the movement of water from one side to another side of a semipermeable membrane.

The main property of salts that helps to understand the differentiation between the molarity and osmolarity is the salts Ionization.  One mole Na+ and one mole of Cl- is produced by the dissociation of a mole of sodium chloride occurs. The diffusion of water is the osmosis. Here, the one molar sodium chloride solution produces a osmotic pressure which is high than one molar glucose solution and this will not undergo dissociation.