Seawatter

On average, seawatter in the warld's oceans haes a salinity o aboot 3.5% (35 g/L, or 599 mM). This means that ivery kilogram (aboot ane litre bi vollum) o seawatter has approximately 35 gram (1.2 oz) o dissolved sauts (predominantly sodium (Na⁺
) an chloride (Cl⁻
) ions). Average density at the surface is 1.025 g/ml. Seawatter is denser nor baith fresh watter an shire watter (density 1.0 g/ml @ 4 °C (39 °F)) acause the dissolved sauts add mass withoot contributing significantly tae the vollum. The freezing pynt o seawatter decreases as saut concentration increases. At teepical salinity it freezes at aboot −2 °C (28 °F). The cauldest seawatter iver recordit (in a liquid state) wis in 2010, in a stream unner an Antarctic glacier, an meisured −2.6 °C (27.3 °F).