L1 /   
10
CH3041
FRESHWATER vs SEAWATER
C 0.85 (42%) 2     (0.2%) HCO3-
Ca 0.33 (17%) 10   (0.9%) CaSO4
Na 0.23 (12%) 470 (41.9%) Na+
Cl 0.16 (8%) 550 (49.0%) Cl-
Si 0.16 (8%) 0.1  (0%) H4SiO4
Mg 0.14 (7%) 53   (4.7%) MgSO4
S 0.09 (4%) 28   (2.5%) NaSO4-
K 0.03 (1%) 10   (0.9%) K+
MgSO4 is referred to as an ion pair. A loose complex  with H2Os separating the ions. 10%
Major Ion Composition (mmol l-1 , global averages)
Element Riverwater Seawater Species