| Atomic number: | 17 |
| Atomic weight: | 35.4527 |
| Average concentration in ocean: | 546 mmol/kg |
| Residence time: | 87,000,000 years |
Distribution in ocean
Chlorine is the most abundant element dissolved in seawater. It has a
conservative distribution that
varies only due to differences in evaporation or precipitation in the water that
sank to form intermediate or deep waters in the sea (data).
Concentrations are higher in the Atlantic because that ocean is saltier.
Speciation
Chlorine is present in seawater as the chloride ion, Cl-.
Residence time
The chloride residence time was calculated from the global average river input
after correcting for man's impact on the chloride content of modern rivers
(Berner and Berner, 1987).
Analysis
Chloride is determined by a Mohr titration using AgNO3 to form AgCl
precipitate.