In this paper we examine in detail the effects of forcing the thermokinetic or the chain-thermal model of hydrocarbon oxidation (proposed by B. F. Gray and C. H. Yang) in a Continuously Stirred Tank Reactor (CSTR). Here, the reaction has been subjected to periodic modulation of the input and output flows of chemicals. This investigation has uncovered rich non-linear dynamical characteristics including primary resonances, super and sub-harmonic resonances, quasi-periodic solutions and chaotic oscillations. These regions of chaos are normally interrupted by windows of periodic behaviour. The transitions to chaos were mainly found to be of three types: Feigenbaum period-doubling cascade, Ruelle-Takens-Newhouse approach through quasi-periodicity, and intermittency. The presence of these chaotic solutions was confirmed by computing the Lyapunov exponents. The results presented here are of potential benefit to industrial practice, since they show great increases in product selectivity when appropriate operating conditions are chosen in this forcing strategy.