Reaction mechanism energy dependent

Because at 80°C, S — 0.5, and at 100°C no sulfochlorination at all takes place, the process is run between 35 °C and 40°C. The selectivity also depends on the molar ratio of sulfur dioxide to chlorine. Provided that there is a fine dispersion of the reacting gases in the alkane for a molar ratio of 3, the selectivity approaches 0.98 (Fig. 5). Sufficient turbulence in the reaction medium (supported by additional mechanical energy) means that the sulfochlorination itself proceeds at the gas-liquid interface. 

In chemical equilibria, the energy relations between the reactants and the products are governed by thermodynamics without concerning the intermediate states or time. In chemical kinetics, the time variable is introduced and rate of change of concentration of reactants or products with respect to time is followed. The chemical kinetics is thus, concerned with the quantitative determination of rate of chemical reactions and of the factors upon which the rates depend. With the knowledge of effect of various factors, such as concentration, pressure, temperature, medium, effect of catalyst etc., on reaction rate, one can consider an interpretation of the empirical laws in terms of reaction mechanism. Let us first define the terms such as rate, rate constant, order, molecularity etc. before going into detail. 

When R is the reactivity of the atom i in the appropriate reaction mechanism, it represents the activation energy required to produce the reactive intermediate. It depends on the ligand 3D structure and on the mechanism of reaction. Therefore, R, is a score proportional to the reactivity of the ligand atom i in a specific reaction mechanism. 

---