Which term describes the concentration of salt in a solution?

The term that describes the concentration of salt in a solution is salinity. Salinity specifically refers to the amount of dissolved salts, primarily sodium chloride, in water. This measurement is crucial in various scientific fields, including environmental science, marine biology, and oceanography, as it influences the behavior of organisms in aquatic environments, as well as chemical processes in those systems.

On the other hand, osmosis refers to the movement of water across a semi-permeable membrane, driven by differences in solute concentration. Hydration describes the process of water molecules surrounding and interacting with solute molecules, which can impact their behavior in a solution but does not specifically measure salt concentration. Filtration is a physical process used to separate solids from liquids or gases using a filter, and while it can help in purifying solutions, it does not pertain to measuring the concentration of salt. Therefore, salinity remains the most accurate term for describing the concentration of salt in a solution.