What term refers to the concentration of a solution measured by the total number of solute particles per kilogram?

The term that refers to the concentration of a solution measured by the total number of solute particles per kilogram is osmolality. This concept is crucial in various scientific and medical contexts, particularly in understanding how solutions affect cell behavior and bodily functions.

Osmolality specifically focuses on the number of solute particles, taking into account all particles in the solution, including ions and molecules, which significantly impacts the colligative properties of solutions. This makes it an important measurement when considering fluid shifts between compartments in the body, such as during hydration or dehydration states.

While other terms like tonicity, osmosis, and concentration are related concepts, they describe different aspects of solutions. Tonicity refers to the effect of a solution on cell volume based on the solute concentration inside the cell versus outside. Osmosis is the movement of solvent molecules across a semipermeable membrane from a region of lower solute concentration to one of higher solute concentration. Concentration is a more general term that may refer to the amount of solute present but doesn't specify the measurement per kilogram of solvent, which is key to understanding osmolality.