Question

In a reactor two stream are entering, one with H2 at 10 atm and 27^oC, and another with O2 at 10 atm and 0^oC, producing H2O2, H2O, and O2 at 10 atm and 23^oC, what are the total degrees of freedom?

(a) 12

(b) 17

(c) 19

(d) 23

The question was asked in semester exam.

Question is taken from Degrees of Freedom Analysis topic in chapter Energy Balances that Include the Effects of Chemical Reaction, Ideal Processes, Efficiency and the Mechanical Energy Balance and Heats of Solution and Mixing of Basic Chemical Engineering

Answer 1

Correct answer is (b) 17

The explanation: Total species = 1 + 1 + 3 = 5, total stream flows = 3, stream pressures = 3, stream temperatures = 3, heat released = 1, and extent of reaction = 2, => degrees of freedom = 5 + 3 + 3 + 3 + 1 + 2 = 17.