OxygenSolubilityWater: Oxygen solubility in water

In chepec/water: Oxygen Solubility in Water

Description

Oxygen solubility in water which is in contact with air saturated with water vapour, as a function of temperature and at a total pressure of 760 torr.

Usage

OxygenSolubilityWater(temperature)

Arguments

temperature

numeric, vector. In degrees Celsius.

Details

Some background: as the temperature of a gasesous solution is raised the gas is driven off until complete degassing occurs at the boiling point of the solvent. This variation of solubility with temperature can be derived from thermodynamic first principles. But the variation of oxygen solubility in water cannot be represented by a simple relationship (derived from thermodynamic first principles), and so more complicated expressions which are fitted to empirical data have to be used.

Hitchman, Measurement of Dissolved Oxygen, 1978 reproduce a table by Battino and Clever (1966) that presents experimental values of the so-called Bunsen absorption coefficient (this is the volume of gas, at 0 C and 760 torr, that, at the temperature of measurement, is dissolved in one volume of the solvent when the partial pressure of the gas is 760 torr) recorded by eleven research groups up until 1965. The standard error of the mean value is never greater +-0.5 probably accurate enough for most applications. Hitchman notes that the data in this table can be fitted by two forms of equations: one form obtained from Henry's law (under the restriction that the partial pressure of the gas remains constant), and another form by describing the variation with temperature by fitting a general power series. The latter approach is used in this function.

Hitchman chooses to fit a fourth degree polynomial, and found that the square of the correlation coefficient was 0.999996.

For more background and detailed derivation of the formula used here, see section 2.2 (pp. 11) in Hitchman.

This formula is strictly speaking only valid for 0 < T < 50 celsius. The function will return values outside this range, but with a warning.

Value

a dataframe with the following columns: + "temperature" same as the supplied temperature + "g/cm-3" oxygen solubility expressed as gram per cubic cm + "mg/L" ditto expressed as milligram per litre + "mol/L" ditto expressed as moles per litre (molarity) + "permoleculewater" number of O2 molecules per molecule of water Note: mg/L is equivalent to ppm by weight (since water has approx unit density in the temperature range 0-50 Celsius).

Examples

## Not run: 
OxygenSolubilityWater(22)
OxygenSolubilityWater(c(2, 7, 12, 30))

## End(Not run)

chepec/water documentation built on Jan. 6, 2022, 1:33 a.m.