sory,,i'm forget,,
The value of k, needs to have the function of temperature, k = f (T), so you must seek the values of A and Ea, the equation k = A exp -Ea/RT,,
as adiabatic, the temperature can be decreased or raising, therefore, the value of k must be a function of temperature k = f (T), unlike the case when Isothermal,, k is not a function of temperature,,