Single-Route Linear Catalytic Mechanism: A New, Kinetico-Thermodynamic Form of the Complex Reaction Rate

For a complex catalytic reaction with a single-route linear mechanism, a new, kinetico-thermodynamic form of the steady-state reaction rate is obtained, and we show how its symmetries in terms of the kinetic and thermodynamic parameters allow better discerning their influence on the result. Its reciprocal is equal to the sum of n terms (n is the number of complex reaction steps), each of which is the product of a kinetic factor multiplied by a thermodynamic factor. The kinetic factor is the reciprocal apparent kinetic coefficient of the i-th step. The thermodynamic factor is a function of the apparent equilibrium constants of the i-th equilibrium subsystem, which includes the (n−1) other steps. This kinetico-thermodynamic form separates the kinetic and thermodynamic factors. The result is extended to the case of a buffer substance. It is promising for distinguishing the influence of kinetic and thermodynamic factors in the complex reaction rate. The developed theory is illustrated by examples taken from heterogeneous catalysis.

Evaluation of the Buffer Capacity of Crude Rubbers

The hypothesis was advanced in the preceding paper that an important factor in determining the rate of cure of rubber is the acid-base equilibrium developed during vulcanization and that such an equilibrium is determined to a large extent by the nature and quantity of the latex serum substances remaining in the crude rubber mass. In effect, this serum material was regarded as a buffer substance. If this were true, it follows that differences in the buffer capacities of various crude rubbers should be demonstrable and, in the following discussion, two sets of experiments designed with this object in view are described.