Atkins & de Paula:
Physical Chemistry for the Life Sciences
It is found experimently for many reactions that a plot of ln(k) against 1/T gives a straight line. This behaviour is normally expressed mathematically by introducing two parameters, one representing the intercept and the other the slope of the straight line, and writing the Arrhenius equation
The parameter A (s-1 for a first-order reaction and L mol-1s-1 for a second-order reaction), which is given by the intercept of the line at 1/T = 0, is call the pre-exponential factor. The parameter Ea (activation energy, J mol-1) is obtained from the slope of the line (-Ea/R), where R is the gas constant (J mol-1K-1).
To calculate the Arrhenius parameters enter data pairs (T, k) and then click the Plot tab.
To see the value of parameters click the Least-Squares Analysis tab. To pick off a value on the
graph, move your cursor to the desired location then click and hold.