Asked in Elements and Compounds
How much percent of sodium and chlorine are present in sea water?
The salinity in sea water varies from place to place and from time to time. One widely used reference* gives the following averages: sodium, 1.05 g/litre and chlorine (predominantly chloride ions), 1.90 g/litre.
*Handbook of Chemistry and Physics, 66th Ed., page F-148.