Question

The feed of a process simulator is 10 mole with enthalpy 2 J/mole, the heat input is 15 J, and the work performed is 10 J, what will be the product enthalpy if mole of the product are 5?

(a) 2 J/mole

(b) 3 J/mole

(c) 4 J/mole

(d) 5 J/mole

I had been asked this question during an interview for a job.

The question is from Unsteady-State Material and Energy Balances topic in section Humidity Charts & their Use, Analysis of the Degrees of Freedom in a Steady – State Process, Solving Material and Energy Balances Using Process and Unsteady State Material and Energy Balances of Basic Chemical Engineering

Answer 1

Correct option is (d) 5 J/mole

For explanation: Energy balance, 5*H = 10*2 + 15 – 10 = 25, => H = 5 J/mole.