Concept information
Preferred term
proton affinity
Definition(s)
- The proton affinity (PA, Epa) of an anion or of a neutral atom or molecule is the negative of the enthalpy change in the reaction between the chemical species concerned and a proton in the gas phase : A⁻ + H ⁺ → HA, B + H⁺ → BH⁺. These reactions are always exothermic in the gas phase, i.e. energy is released (enthalpy is negative) when the reaction advances in the direction shown above, while the proton affinity is positive. This is the same sign convention used for electron affinity. The property related to the proton affinity is the gas-phase basicity, which is the negative of the Gibbs energy for above reactions, i.e. the gas-phase basicity includes entropic terms in contrast to the proton affinity. (Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/wiki/Proton_affinity)
Broader concept(s)
In other languages
-
French
URI
http://data.loterre.fr/ark:/67375/MDL-KV3MMM1C-8
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