Two pound moles of ammonia are burned in an SSSF process with x lb mol of oxygen.

Question:

Two pound moles of ammonia are burned in an SSSF process with x lb mol of oxygen. The products, consisting of H2O, N2, and the excess O2, exit at 400 F, 1000 lbf/in 2.
a. Calculate x if half the water in the products is condensed.
b. Calculate the absolute entropy of the products at the exit conditions.