53. The rate constant of a reaction at temperature 200K is 10 times less than the rate constant at 400 K. What is the activation energy (E_a ) of the reaction (R = gas constant)
(a) 1842.4 R              (b) 921.2 R             (c) 460.6 R                (d) 230.3 R

54. In respect of the equation $K=A{e}^{-E_a/RT}$in chemical kinetics, which one of the following statement is correct