The activation energy of the reaction may be calculated using the previously determined slope, and the Arrhenius equation to calculate the value of the rate constant at 25 °C. Alternatively, you can simply extrapolate the straight line plot of ln(k) vs. I/T, read off the value of ln(k), and determine the value of k. k (25 °C) = my slope is: -16538 my k values are: 0.00057, 0.0017, 0.00525, 0.0238, 0.1386. My activation energy is: 137.5 and my temperatures are: 45, 55, 65, 75, and 80 in celsius. the order of temp and k values correspond to each other.