Let us move on from pure water (freshwater) to seawater. Seawater is a mixture of about 96.5% pure water and 3.5% dissolved minerals, collectively known as the salt content, or salinity.
Because the amount of minerals added to pure water is small, the density dependence on temperature in seawater does not differ much from the situation we found for pure water.
Let us then investigate the effect of salinity on density: Let us keep the temperature constant and vary only the salinity. How do you think does the presence of salt affect the density? Does the density increase if we add salt, or does it decrease?
© 2000 M. Tomczak