
59Introduction to Kinetics and Chemical Reactors
Rate of adsorption of B, r
B
, is
rkCC
BBBl
Bl
(2.151)
Step 2 (Surface Reaction):
Reaction between A and B chemisorbed to the adjacent sites leading to the formation of
product C that is adsorbed to one of the two adjusted sites leaving the other site vacant
Al Bl Cl l
r
A chemisorbed molecule of A cannot react with any chemisorbed molecule of B other
than the one chemisorbed to a site adjacent to it. So the forward rate is taken as propor-
tional to the concentration of adsorbed A (C
Al
) multiplied by the fraction of the adjacent
sites (θ
B
) occupied by B molecules. This fraction ...