from empirical fits, and one function that returns water vapour pressure (simply interpolates based on the previously available dataset).master

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`% 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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```
``` |
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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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```
``` |
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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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```
``` |
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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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```
``` |
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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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`% 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{VapourPressureWater}` |
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`\alias{VapourPressureWater}` |
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`\title{Vapour pressure of water}` |
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`\usage{` |
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`VapourPressureWater(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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`vapour pressure of water, in kilopascal` |
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`}` |
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`\description{` |
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`Vapour pressure of water as a function of temperature` |
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`This function returns the vapour pressure of water at the given` |
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`temperature(s) from the common::vapourwater dataset.` |
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`}` |
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`\examples{` |
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`\dontrun{` |
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`VapourPressureWater(45)` |
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`VapourPressureWater(c(20, 25, 45, 60))` |
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`}` |
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`}` |

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