# How does salinity affect the density of water?

The density of pure water is $1.00$ $g \cdot c {m}^{-} 3$ at a given temperature. Should salts be dissolved in the water, and the volume remains reasonably constant, the density of the solution should markedly increase from $1.00$ $g \cdot c {m}^{-} 3$. A solute binds water molecules around itself in a coordination sphere, and should a salt be dissolved, both anion and cation must be solvated; hence an increase in solution density with respect to water.