Constant, fundamental CODATA

The Ionization limit of neutral argon (127109.9 0.1 cm" ) reported by Moore (j ) Is adopted as a H"(0 K) for Ar (g). The Ionization limit Is converted from cm to kJ mol" using the factor, 1 cm" = 0.01196266 kJ mol", which Is derived from the 1973 CODATA fundamental constants (2). The uncertainty In the Ionization limit corresponds to an uncertainty of 0.001 kJ mol In the enthalpy of formation. Rosenstock et al. (9) and Levin and Lias (J ) have summarized additional Ionization potential and appearance potential data. A recent atomic spectroscopic study by Mlnnhagen (j ) yielded an Ionization potential within 0.13 cm" of our adopted value. Gurvlch et al. (8) and Wagman et al. (1 ) adopted the same Ionization potential, but the use of slightly different fundamental constants by Wagman et al. (10) resulted In a enthalpy of formation difference of 0.015 kJ mol". ... 

The thermodynamic functions of the proton gas are calculated using the recent CODATA fundamental constants (2) and assuming that the proton is an ideal monatomic gas. Since there is no electron associated with this species, there is only a translational contribution to the therraochemical function. 

CODATA fundamental constants (2). The uncertainty in the ionization limit is estimated to be 0.2 cm" which corresponds to an uncertainty of 0.002 kJ mol in the enthalpy of formation. Gurvich et al. (8) adopted the same ionization potential, but the... 

K) (1 ) using the spectroscopic value of IP(W) = 64400 1.20 kJ mol" ) from Moore (2). The ionization limit is converted from cm" to kJ mol" using the factor, 1 cm", which is derived from the 1973 CODATA fundamental constants (3) additional ionization and appearance potential data. 

CODATA fundamental constants, 1-1 to 11 CODATA Key Values for Thermodynamics, 5-1 to 3... 

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