molweight {marelac}

Molecular Weight of a Chemical Species

Description

Calculates the molecular weight of chemical species.

Usage

molweight(species)

Arguments

species

character vector with chemical species whose molecular weight is requested.

Details

Molecular weights of chemical elements may vary due to different isotope compositions, depending on geology, industrial processes or biological activity. Please consult the IUPAC Technical report about the details. The function returns NA for elements (and their compounds) which have no stable isotopes (except U, Th, Pa).

Value

Vector with the molecular weights in g/mol.

Note

This function uses text parsing of chemical formulae, it is strictly case sensitive.

Author(s)

Thomas Petzoldt

References

Wieser ME, 2006. Atomic weights of the elements 2005 (IUPAC Technical Report). Pure Appl. Chem. 78(11), 2051–2066. doi:10.1351/pac200678112051

See Also

AtomicWeight, molvol, redfield

Examples

molweight("CO2")
molweight("HCO3")
molweight("H")
molweight("H3PO4")

## eicosapentaenoic acid (EPA)
molweight("CH3CH2CHCHCH2CHCHCH2CHCHCH2CHCHCH2CHCH(CH2)3COOH")
molweight("C20H30O2")

## works also with vectors
molweight(c("C2H5OH", "CO2", "H2O"))
molweight(c("SiOH4", "NaHCO3", "C6H12O6", "Ca(HCO3)2", "Pb(NO3)2", "(NH4)2SO4"))

## note that chemical formulae are case-sensitive
molweight("Co") # cobalt
molweight("CO") # carbon monoxide


## from gram to mol
1/molweight("CO3")