1.3 Variables Affecting the Rate of Reaction In homogeneous systems,Temperature, Pressure and Composition In heterogeneous systems,besides T,P &C, mass heat transfer some times play important roles 99 • 1.3 Variables Affecting the Rate of Reaction • In homogeneous systems, Temperature, Pressure and Composition • In heterogeneous systems, besides T, P &C, mass & heat transfer some times play important roles