Physical Chemistry Citations

garfinkm@drexel.edu


A Thermodynamic-Probabilistic Analysis of Diverse Homogenous Stoichiometric Chemical Reactions
M. Garfinkle; J. Physical Chemistry; 106A (2002) 490

ABSTRACT - Research into the nature of atom-migration dynamics has demonstrated a linear relationship between the driving force for these processes and the probability for forward as opposed to reverse reaction. An assumption that this observation would prove to be just as valid for stoichiometric chemical reactions would allow a thermodynamic-probabilistic model to be developed. Using this linear approach, the resulting probabilistic reaction path developed was correlated with empirical kinetic data. The exceedingly high correlation between the probabilistic path and the empirical data over the entire range of experimental observations constitutes definitive evidence that stoichiometric chemical reactions are themselves purely stochastic processes and moreover that the linear assumption is in fact valid.

 
The Thermodynamic Natural Path in Chemical Reaction Kinetics
M. Garfinkle; Discrete Dynamics in Nature and Society; 4 (2000) 145

ABSTRACT - The Natural Path approach to chemical reaction kinetics was developed to bridge the considerable gap between the Mass Action mechanistic approach and the non-mechanistic irreversible thermodynamics approach. The Natural path approach can correlate empirical kinetic data with a high degree of precision, as least equal to that achievable by the Mass-Action rate equations, but without recourse to mechanistic considerations. The reaction velocities arising from the particular rate equation chosen by kineticists to best represent the kinetic behavior of a chemical reaction are the natural outcome of the Natural Path approach. Moreover, by virtue of its thermodynamic roots, equilibrium thermodynamic functions can be extracted from reaction kinetic data with considerable accuracy. These results support the intrinsic value of the Natural Path approach.

 
Mass Action and the Natural Path
M. Garfinkle; J. Non-Equilibrium Thermodynamics; 17 (1992) 281

ABSTRACT - A thermodynamic approach to the study of chemical reaction dynamics has appeared in a series of papers wherein reactions are described in terms of the rate of change of a thermodynamic function rather than in the conventional terms of the rate of the concentrations of reacting species. A comparison of the extent of validity of these alternative approaches is the subject of this study, which takes the form of both a critique of recently published papers in this field and a discussion of these alternative approaches in terms of probabilistic modeling and Markovian analysis.

 

Natural Path in Chemical Thermodynamics
M. Garfinkle; J. Physical Chemistry; 93 (1989) 2158

ABSTRACT - Past studies have demonstrated that homogeneous chemical reactions in a closed isothermal system follow a singular thermodynamic reaction path that can be described by an affinity-decay expression that is consistent with all thermodynamic considerations. From the analytical description of this path, reaction velocities have been determined without reference to mechanistic considerations and standard Helmholtz functions have been extracted from empirical kinetic data. These calculated values were found to be in agreement with the values directly measured by kineticists and thermodynamicists, respectively. The present paper demonstrates that only for a chemical reaction traversing this singular thermodynamic reaction path can the affinity decay rate be determined between reaction initiation and equilibrium, even for reactions that can proceed along any of several alternative mechanistic reaction paths.

 

 
Extraction of Standard Helmholtz Functions from Affinity Rate Data
M. Garfinkle; Faraday Transactions I; 81 (1985) 717

ABSTRACT - An extrapolation procedure to extract standard Helmholtz functions from empirical kinetic data without reference to reaction mechanisms has been developed using an analytical description of the affinity decay rate.

 

Temperature Dependency of the Affinity Decay Rate
M. Garfinkle; J. Chemical Physics; 79 (1984) 3640

ABSTRACT - The temperature dependency of the affinity decay rate of the reacting system was found to be analogous to the temperature dependency of the Helmholtz function of the equilibrium system. Consequently, standard state internal energies could be computed from kinetic data and were found to be comparable to experimental internal energies.

 

Affinity Decay Rates for the Recombination of Several Monatomic Halogens
M. Garfinkle; Material Chemistry & Physics; 8 (1983) 251
ABSTRACT - Several potential limitations on the determination of the affinity decay rate for very rapid reactions are examined. It is found that under certain circumstances the initial reaction state in terms of chemical kinetics can differ from the initial reaction state in terms of chemical thermodynamics. Because the elapsed time must refer to some initial state, his discrepancy can constitute a potential source of error. Thermal effects associated with very rapid reaction velocities are also examined.
 
Reaction Velocities and the Affinity Decay Rate
M. Garfinkle; J. Chemical Physics; 79 (1983) 2779

ABSTRACT - Reaction velocities are calculated for several chemical reactions with diverse mechanisms from thermodynamic considerations alone. These are compared to reaction velocities computed in the conventional manner from mechanistic considerations. The comparisons indicate that linear phenomenological relationship between chemical affinity and reaction velocity cannot be justified and there exists a basic incompatibility between the thermodynamic and the mechanistic approach to reaction kinetics.

 

Non-Equilibrium Thermodynamics of Closed-System Reaction
M. Garfinkle; Material Chemistry & Physics, 7 (1982) 359

ABSTRACT - Stoichiometric chemical reactions in a closed isothermal system are studied in terms of classical and statistical thermodynamics. It is demonstrated that the affinity decay rate in such a system is independent of reaction mechanism. On this basis a general thermodynamic description of the reactions is provided, valid for reactions with diverse mechanisms. In contrast to earlier approaches dealing only with systems close to equilibrium, the present formalism is applicable to systems arbitrarily far from equilibrium. The agreement between computation and experiment is distinctly better than in calculations based on absolute rate theory.


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