The activation energy of a reaction is 225 k Cal mol-1 and the value of rate constant at 40°C is 1.8 ×10^−5 s^−1 . Calculate the frequency factor, A.

SOLUTION:

Here, we are given that

Ea = 22.5 kcal mol-1 = 22500 cal mol-1

T = 40°C = 40 + 273 = 313 K

k = 1.8 × 10-5 sec-1

Substituting the values in the equation

log A = log (1.8) −5 + (15.7089)

log A = 10.9642

A = antilog (10.9642)

A = 9.208 × 101^0 collisions s^−1