The ions in the salt dissociate and are surrounded by water molecules forming clusters of a size greater than that of the original ion:

image

Once the ion is surrounded by water molecules, a second layer of molecules is formed, which are linked by bridges:

image

If an electric field is applied to water with salt ions, the latter begin to move towards the positive poles:

image

The electrical conductivity as a function of salinity and temperature that is explained by the greater presence of ions and the greater mobility at higher temperatures:

image

Electrical conductivity as a function of pressure and temperature:

image

The specific conductivity measured in seawater under atmospheric pressure can be empirically represented as

equation

The following table shows electrical conductivity as a function of salinity:

image

Dado que la resistencia del agua marina depende de su salinidad, se puede medir la resistencia para determinar el nivel de salinidad. Esto se hace comparando las conductividades de una muestra de agua marina con una soluci n standard de KCl (clorato de potasio). Se miden la conductividad especifica de ambas muestras a una temperatura de 15C y 1 atm de presi n y establece la relaci n\\n\\n

$K=\sqrt{\displaystyle\frac{\gamma_w}{\gamma_{KCl}}}$

y calcula la salinidad con

equation

con

a_0=0.0080

a_1=-0.1692

a_2=25.3851

a_3=14.0941

a_4=-7.0261

a_5=2.7081