Information theory for marginal distributions: Application to energy disposal in an exothermic reaction

Information theory is used to make the best estimate of a multi-variable probability distribution from one of its marginal distributions. The method developed is used to examine the relationship between the distributions of available energy over two different degrees of freedom of the products of the reaction of H+NO2→OH+NO. It is ascertained that a molecular beam experiment to measure the product translational energy distribution and experiments whereby the internal energy distribution in OH are determined from infrared chemiluminescence and laser-induced fluorescence are not redundant.