303
E
T
T
R







Subtracting equation (3 20) from (3 21), we obtain
ln k2 – ln k1 = 
a
1
E
RT  – 
a
2
E
RT
ln k
k
E
R
T
T
2
1
1
2
1
1
=
−




a
log kk
E
R T
T
2
1
1
2
2 303
1
1
=
−




a
(3