Kyobe, J. W. P.J. W.M. P.Akwilapo, Leonard D.Parmena, D.2016-07-112016-07-112009-12Kyobe, J.W.M.P., Akwilapo, L. and Parmena, D.S., 2012. Theoretical Aspects of the Activation and Its Access to the Activation Energies of Gas Phase Chemical Reactions, Part I. TaJONAS: Tanzania Journal of Natural and Applied Sciences, 1(2), pp.120-137.1821-7249http://hdl.handle.net/20.500.11810/3071Full text can be accessed at http://www.sjutpress.org/ojs/index.php/tajonas/article/view/19/25Various bonds in molecules accumulate energies under rising temperature until the energies are sufficient to promote dissociation. The activation energy of a chemical reaction AB → A + B and the bond dissociation energy, D(A-B) are calculated on the basis of the A―B bond stretching vibration ( cm-1 ). The activation energies, Ea = 883, 407, 249.31, and 437.7 kJmol-1 are calculated for nitrogen, hydrogen chloromethane and water respectively. The dissociation energies D(N-N) = 945.07, D(H-H) = 435.5, while for C2H5Cl the D(C-H) = 409.22 and D(C-Cl) = 341.75 kJmol-1 are also calculated. In each case, the theory confirms the experimental findingsenVibrational energyTranslational energyRotational energy Dissociation temperatureDegrees of freedomJournal Article