This work deals with the development and application of physico-chemical models for non-equilibrium hypersonic flows. With the most recent and accurate ab-initio Potential Energy Surfaces, relevant processes such as dissociation and particle exchange (e.g. Zel’dovich reactions) are analyzed based on State-to-State kinetics data generated via Quasi Classical Trajectory calculations. The reduction of these kinetics mechanisms to a more tractable form for multi-dimensional flow predictions is realized by grouping states within bins. Group-averaged kinetic parameters such as rate coefficients are computed either directly based on transition data for individual states or while executing trajectories. This latter strategy allows for treating diatom-diatomsystems forwhich a rovibrationally resolved State-to-State approach is impractical. The accuracy of the proposed models is assessed in zero-dimensional chemical reactor calculations. Extensive comparisons against literature data are also presented.