Question

For the parallel reaction A → B and A → C, of rate constants k1 and k2 respectively, both reactions of order 1, the rate expression is given as ____

(a) (-rA) = k1CA + k2CA

(b) (-rA) = k1CA – k2CA

(c) (-rA) = k2CA

(d) (-rA) = k1CA

The question was asked by my college director while I was bunking the class.

Origin of the question is Reducing the Size of Kinetic Models topic in portion Elements of Reaction Kinetics of Chemical Reaction Engineering

Answer 1

Correct option is (a) (-rA) = k1CA + k2CA

For explanation I would say: For a zero order reaction, \(\frac{-dC_A}{dt}\) = k1CA + k2CA

A forms two products: B and C. The concentration of A decreases as the reaction progresses.