2. Salinity
As already mentioned above, sea water contains 3.5% salts, dissolved gases, organic materials and particles had dissolved. The presence of salts affects the physical properties of seawater (density, compressibility, freezing, the temperature where the density becomes maximum) a few levels but did not specify. Some properties (viscosity, light absorption) was not significantly affected by salinity. Two properties are largely determined by the amount of salt in the sea is the electrical conductivity (conductivity) and osmotic pressure.
The main salts contained in seawater are chloride (55%), sodium (31%), sulfate (8%), magnesium (4%), calcium (1%), potassium (1%) and the rest (less than 1%) teridiri of bicarbonate, bromide, borak acid, strontium and fluoride. Three main sources of salts in the sea is the land of rock weathering, volcanic gases and the circulation of hydrothermal holes (hydrothermal vents) in the deep ocean.
Ideally, salinity is the sum of all salts in grams for each kilogram of sea water. In practical terms, to measure the salinity is difficult, therefore, salinity pricing is done by reviewing only the most important component of chloride (Cl). Chloride content of established in 1902 as the number of
grams of chloride ions in one kilogram of sea water if all the halogen is replaced by chloride. This reflects the determination of the chemical process of titration to determine chloride content.
Salinity is set in 1902 as the total number of grams of dissolved material in one kilogram of sea water when all carbonate converted to oxides, all bromide and iodine converted into chloride and all organic material is oxidized. Furthermore the relationship between salinity and chloride are determined through a series of basic laboratory measurement based on sea water samples around the world and is expressed as:
S (o / oo) = 0.03 +1805 Cl (o / oo) (1902)
Symbol o / oo (reads per mile) is a part per thousand. 3.5% salt content 35o/oo or equal to 35 grams of salt in one kilogram of sea water.
to be continued........