Calculate the Conversion Rate in a Gas Phase Reaction

Question

The elementary gas-phase reaction A → 2B is carried out in a PFR.  The feed is at 400 K with an 80% A/20% B molar mixture fed at 1.0 mol/s. The reactor is isothermal at 400 K and the exit stream has a 0.20 mole fraction of A and 0.80 mole fraction of B. What is the conversion of A?

a) 45.5%
b) 20%
c) 33%
d) 80%
e) 62.5%
f) 75%

Summary

The question belongs to Chemical Engineering and it is about calculating gas phase reaction of A →2B carried out in PFR. The conversion rate of A has been calculated in the solution.