Question

A liquid phase reaction occurring in a CSTR follows first order dynamics. The feed rate is 500m^3/min. Initial concentration of the feed is 50mol/m^3. If the reaction conversion is 50% and the reaction is carried out in a 0.5 m^3 CSTR, what is the value of rate constant?

(a) 40

(b) 20

(c) 10

(d) 5

This question was addressed to me in class test.

Question is from Conversion and Reactor Sizing topic in portion Ideal Reactors for a Single Reaction, Conversion and Reactor Sizing of Chemical Reaction Engineering

Answer 1

The correct answer is (b) 20

Explanation: FA0 XA = (-rA)V

(-rA) = kCA0(1 – XA)

500 × 0.5 = k × 50 × (1-0.5) × 0.5

k = 20.