We present an experimental and computational study of hypersonic flow with high enthalpy effects over a 25°-55° double-cone model. All experiments were performed in the LENS facility with nitrogen, oxygen, and oxygen-argon mixtures as the test gas. Heat-flux to the model and surface pressure measurements were made over a variety of free-stream conditions. The current experiments were designed to explore the effect of chemical reactions in the experiments by making direct comparisons with CFD predictions. Simulations of all the experiments were performed and the comparisons between measurements and CFD predictions yielded mixed results. Comparisons are favorable at low enthalpy nitrogen and oxygen flows. Poor agreement was observed at higher levels of total enthalpy with both pure oxygen and oxygen-argon mixtures.