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66 lines
2.7 KiB
R
66 lines
2.7 KiB
R
% Generated by roxygen2: do not edit by hand
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% Please edit documentation in R/chemistry-tools.R
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\name{OxygenSolubilityWater}
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\alias{OxygenSolubilityWater}
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\title{Oxygen solubility in water}
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\usage{
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OxygenSolubilityWater(temperature)
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}
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\arguments{
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\item{temperature}{numeric, vector. In degrees Celsius.}
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}
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\value{
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a dataframe with the following columns:
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+ "temperature" same as the supplied temperature
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+ "g/cm-3" oxygen solubility expressed as gram per cubic cm
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+ "mg/L" ditto expressed as milligram per litre
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+ "mol/L" ditto expressed as moles per litre (molarity)
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+ "permoleculewater" number of O2 molecules per molecule of water
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Note: mg/L is equivalent to ppm by weight (since water has approx
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unit density in the temperature range 0-50 Celsius).
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}
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\description{
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Oxygen solubility in water which is in contact with
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air saturated with water vapour, as a function of
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temperature and at a total pressure of 760 torr.
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}
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\details{
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Some background: as the temperature of a gasesous solution is raised the
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gas is driven off until complete degassing occurs at the boiling point
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of the solvent. This variation of solubility with temperature can be
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derived from thermodynamic first principles.
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But the variation of oxygen solubility in water cannot be represented by a
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simple relationship (derived from thermodynamic first principles), and so
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more complicated expressions which are fitted to empirical data have
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to be used.
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Hitchman, Measurement of Dissolved Oxygen, 1978 reproduce a table by
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Battino and Clever (1966) that presents experimental values of the
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so-called Bunsen absorption coefficient (this is the volume of gas, at 0 C
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and 760 torr, that, at the temperature of measurement, is dissolved in one
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volume of the solvent when the partial pressure of the gas is 760 torr)
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recorded by eleven research groups up until 1965. The standard error of the
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mean value is never greater +-0.5%. The mean values from this table are
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probably accurate enough for most applications.
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Hitchman notes that the data in this table can be fitted by two forms of
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equations: one form obtained from Henry's law (under the restriction that
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the partial pressure of the gas remains constant), and another form by
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describing the variation with temperature by fitting a general power series.
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The latter approach is used in this function.
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Hitchman chooses to fit a fourth degree polynomial, and found that the
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square of the correlation coefficient was 0.999996.
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For more background and detailed derivation of the formula used here,
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see section 2.2 (pp. 11) in Hitchman.
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This formula is strictly speaking only valid for 0 < T < 50 celsius.
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The function will return values outside this range, but with a warning.
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}
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\examples{
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\dontrun{
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OxygenSolubilityWater(22)
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OxygenSolubilityWater(c(2, 7, 12, 30))
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}
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}
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