ABSTRACT
Since 97% of the water on earth is seawater, it is interesting to look at some of its particular physico-chemical properties. Most people think of seawater as containing salt, but in fact it contains a mixture of ions; to date, 60 of the 92 basic elements have been identified in seawater. Table 2.3 gives the average composition of seawater containing 25 g of salt per kilogram, which corresponds to “average” seawater. Bear in mind that if the average concentration of salt is 25 grams per kilogram and we know
that the total volume of the oceans is 1350 million km3, then the total volume of salt is approximately 50 million billion tons!
