Question

Three feeds, 10 mole with H = 15 J/mole, 20 mole with H = 5 J/mole and F1 with 20 J/mole, if enthalpy of the products is H = 15 J/mole, what is the value of F1?

(a) 10 mole

(b) 20 mole

(c) 30 mole

(d) 40 mole

I had been asked this question in a national level competition.

This question is from Solving Energy Balance Problems in section Application of Energy Balances in the Absence of Chemical Reactions and Energy Balances: How to Account for Chemical Reaction of Basic Chemical Engineering

Answer 1

Right choice is (d) 40 mole

For explanation I would say: 10*15 + 20*5 + F1*20 = (30 + F1)*15, => F1 = 40 mole.