Reaction Kinetics

In Chapter 2 we reviewed the principles of chemical thermodynamics that enable us to predict whether or not a particular reaction will take place, under specified conditions, and the quantities of reactants and products present when chemical equilibrium is reached and reaction stops. Thermodynamics therefore provides us with a first test of any scheme of reactions for producing a material: are the reactions feasible at practical temperatures and do they produce the desired material in sufficient yield? An equally important consideration, from the viewpoint of economics, is how rapidly the reaction takes place. A reaction may be thermodynamically feasible but take place so slowly that the productivity of a process involving the reaction is too low. “Too low” here means that the revenue derived from the material produced is too low to justify the investment of capital to build the plant or perhaps even too low to meet the operating costs (labor, energy, raw materials, etc.) of the process. This chapter is concerned with the rate at which reactions take place.