The chlorinity of water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 is defined as the mass of chlorine

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

 equivalent to the total mass of halogen

Halogen

The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style of the periodic table, comprising fluorine , chlorine , bromine , iodine , and astatine...

 contained in 1 kg seawater. It is determined by the Mohr-Knudsen titration

Titration

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the...

, which however neglects fluoride

Fluoride

Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...

.

The halogen concentration of sea water can be expressed in terms of chlorosity which is the number of grams of chloride and chloride equivalents to the bromide in one liter of sea water at 20 °C (68 °F).

Chlorinity is related to chlorosity as,

Chlorinity(^o/_oo) - chlorosity/density

Chorinity is related to salinity as,

Salinity(^o/_oo) = 0.03 + 1.805 x chlorinity