hydrometer

A hydrometer measures the specific gravity of fluids (such as seawater) compared to the density of pure water. In this activity, we constructed our own hydrometer and then used it to measure the densities of fresh and salt water samples.


Salinity is the saltiness or dissolved salt content (such as sodium chloride, magnesium and calcium sulfates, and bicarbonates) of a body of water or in soil. Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. If you add salt to the water solution the hydrometer will float high due to the salt in their.By adding salt to water it does two things. The freezing point of the water goes down and the boiling point of the water actually goes up. It is easier to float in the ocean then a pool because the salt makes it more denser. The degree of compactness in a substance. Temperatures causes differences in the salinity of water because it messes with density.