Question

Mass transfer resistance leads to an increase in the concentration of reactants at the catalyst surface in bulk fluid.

(a) True

(b) False

This question was addressed to me in quiz.

Origin of the question is External Mass Transfer in section Heterogenous Reactions of Bioprocess Engineering

Answer 1

Correct answer is (b) False

Easiest explanation: In absence of mass transfer there is no difference in concentration of reactant at bulk and near the catalyst surface. However, presence of significant mass transfer resistance results in a decrease in the concentration of reactants at the catalyst surface compared to that in the bulk fluid. Consequently, the observed rate is less than the intrinsic rate evaluated at bulk fluid reactant concentration.