Q.

Pre-exponential factors of two different reactions of same order are identical. Let activation energy of first reaction exceeds the activation energy of second reaction by 20 kJ mol-1. If k and k are the rate constants of first and second reaction respectively at 300 K, then ln (k/k) will be ________.

(nearest integer)  [R=8.3 J K⁻¹ mol⁻¹]    [2026]


Ans.

(8)

ARxn(1)product E1

BRxn(2)product E2

Assuming 'A' same for both reaction.

lnk1=lnA-E1300R

lnk2=lnA-E2300R

ln(k2k1)=E1-E2300R=20×1000300R

=8.032