Comment on The Reaction HCl+ + CF4 HCF4+ + Cl: Implications for the Heat of Formation of CF3+ (Ferguson et al., JCP 118, 2130, 2003)
Karl K. Irikura
Prompted by the suggestion that entropy is important in gas-phase ion-molecule reactions, Ferguson et al. recently re-examined the reaction between HCl+ and CF4 (Ferguson et al., JCP 118, 2130, 2003). Both the rate of the reaction and the products formed were in surprising contradiction to an earlier study, but in conformity with the now-accepted thermochemistry of CF3+. After discrediting other problematic reactions, the new result is claimed to obviate the need to invoke a (false) entropy-driven process to explain the experimental discrepancies. Furthermore, it is claimed that including entropy in low-pressure reactions would violate the First Law of thermodynamics. In this comment, additional experimental evidence for the importance of entropy is pointed out, including new evidence from the study by Ferguson et al., and an explanation is offered for the apparent confusion about the role of entropy in low-pressure reactions.
Journal of Chemical Physics
entropy, gas phase, ion chemistry, low pressure, thermochemistry, thermodynamics
Comment on The Reaction HCl+ + CF4 HCF4+ + Cl: Implications for the Heat of Formation of CF3+ (Ferguson et al., JCP 118, 2130, 2003), Journal of Chemical Physics
(Accessed December 10, 2023)