Why does glucose affect osmolarity less than NaCl?

Glucose affects osmolarity less than NaCl primarily because it does not dissociate into ions in solution. Osmolarity is a measure of the total concentration of solute particles in a solution. NaCl, when dissolved in water, separates into two ions: sodium (Na+) and chloride (Cl-). This dissociation effectively doubles the number of particles in the solution, leading to a higher osmolarity.

In contrast, glucose remains as a single molecular entity when dissolved. Since it does not break down into multiple particles, it contributes fewer solute particles to the osmolarity calculation. Therefore, for a given concentration, glucose will have a significantly lesser effect on osmolarity compared to sodium chloride due to its molecular structure and behavior in solution.

Other options, such as glucose being a larger molecule, having a lower molecular weight, or being soluble in fat, do not impact how glucose influences osmolarity in the same way that its non-dissociating property does. These factors are not directly related to the concept of osmolarity and how solute particles are counted in determining a solution's overall osmotic effect.