Chapter 14.7, Problem 18P

Reactants A and B combine to form product P in the liquid phase reaction:

A + B ↔ P

But P reacts further to form an undesired by-product U:

2P ↔ U

The Gibbs free energy and enthalpy of each compound at T = 300 K and P = 1 bar are given in Table P14-18. It is reasonable to assume that both reactions have ΔC_P = 0 and that A, B, P, and U form ideal solutions.

The feed entering a steady-state reactor is 1000 mol/hr each of compounds A and B. The reactor is at a uniform pressure of 1 bar.

1. A. Determine the equilibrium composition of the exit stream at 300 K.
2. B. Determine the equilibrium composition of the exit stream at 600 K.
3. C. The second reaction has a larger equilibrium constant than the first, yet there is, at equilibrium, more P than U. Why?

TABLE P14-18