What percentage of N2O5 will remain after one day? of the rate constant k is equal to -Ea over R where Ea is the activation energy and R is the gas constant, times one over the temperature plus the natural log of A, By graphing. Next we have 0.002 and we have - 7.292. Advanced Organic Chemistry (A Level only), 7.3 Carboxylic Acids & Derivatives (A-level only), 7.6.2 Biodegradability & Disposal of Polymers, 7.7 Amino acids, Proteins & DNA (A Level only), 7.10 Nuclear Magnetic Resonance Spectroscopy (A Level only), 8. Second order reaction: For a second order reaction (of the form: rate=k[A]2) the half-life depends on the inverse of the initial concentration of reactant A: Since the concentration of A is decreasing throughout the reaction, the half-life increases as the reaction progresses. for the activation energy. your activation energy, times one over T2 minus one over T1. Wade L.G. So you can use either version The activation energy for the reaction can be determined by finding the slope of the line.