No it is not possible. Thisis explained with the help of Arrhenius equation according to which k = `Ae(E_(a)//RT)`. If `E_(a)` is zero, then `k=Ae^(0)`= A. This means the rate constant is equal to collision frequency and every collision among the reacting species will lead to the products. Since this does not happen. It is not possible for a chemical reaction to have activation energy equal to zero.
