Areaction has a rate constant of 0.0117 s-1 at 400.0 k and 0.689 s-1 at 450.0 k. calculate the activation energy in kilojoules for this reaction.

By definition we have to:
 LOG (k2 / k1)=(-Ea/R)*(1/T1-1/T2)
 Where,
 k1 = 0.0117 s-1
 K2 = 0.689 s-1
 T1 = 400.0 k
 T2 = 450.0 k
 R is the ideal gas constant
 R = 8.314 KJ / (Kmol * K)
 Substituting
 ln (0.0117/0.689)=-Ea/(8.314)*((1/400)-(1/450))
 Clearing Ea:
 Ea = 122 kJ
 answer
 the activation energy in kilojoules for this reaction is
 Ea = 122 kJ