Critical behaviour in chemically reacting systems-III. An analytical criterion for insensitivity

A form of practical stability, based on experimental reproducibility, is defined, and called insensitivity, to emphasise the most important physical characteristic shown by chemically reacting systems possessing this property. The necessary and sufficient conditions for the insensitivity of an exothermic first order decomposition reaction are obtained rigorously and it is shown without approximation for the well-stirred case that the maximum subcritical dimensionless temperature rise is unity, regardless of the value of parameter ε{lunate} (the inverse of the dimensionless heat of reaction).