What does osmolality measure in a solution?

Osmolality measures the relative number of particles dissolved in a mass of solvent, typically expressed in osmoles per kilogram of solvent. This concept is important in clinical settings because it helps assess the concentration of solutes in bodily fluids, which can reflect various physiological conditions and guide medical treatment.

Measuring osmolality is crucial for understanding fluid balance in the body, as it provides insights into conditions such as dehydration, kidney function, and electrolyte imbalances. When solutes are present in a solution, they contribute to the overall osmotic pressure, which influences how water moves between compartments in the body.

While other options refer to different properties of solutions, only the measurement of the relative number of dissolved particles directly pertains to osmolality, making it the correct choice.