Chemical Reaction Engineering
A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by

External mass transfer
Diffusion within the pellet
Reaction
None of these

ANSWER DOWNLOAD EXAMIANS APP

Chemical Reaction Engineering
The rate expression for a heterogenous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + Kr.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A)

E + ΔHA
ΔHA + ΔHR
E + ΔHA - ΔHR
E

ANSWER DOWNLOAD EXAMIANS APP