The rate constant for a first order reaction at `300^(@)C` for which `E_(a)` is 35 kcal `mol^(-1)` and frequency constant is `1.45 xx 10^(11) s^(-1)` is

Options

A. `10 xx 10^(2) s^(-1)`
B. `5.37 xx 10^(10) s^(-1)`
C. `5 xx 10^(-4) s^(-1)`
D. `7.94 xx 10^(-3) s^(-1)`

Answer

D

Explanation

log `k = log A - (E_(a))/(2.303RT)`
log k = log `(1.45 xx 10^(11)) - (35 xx 10^(3))/(2.303 xx 2 573)`
log k = 11.16 - 13.26 = - 2.1
Taking antilog, `k = 7.94 xx 10^(-3) s^(-1)`