Question

What is the enthalpy of reaction for C2H4 + 3O2 -> 2CO2+ 2H2O, if the conversion of CH4 is 50%, and heat of formation of CH4, O2, CO2, and H2O are 10 J, 0, 6 J and 4 J?

(a) 0

(b) 2 J

(c) 5 J

(d) 10 J

I got this question by my school principal while I was bunking the class.

Question is from Heat (Enthalpy) of Reaction in division 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

Correct answer is (d) 10 J

For explanation I would say: Heat of reaction = 2*4*0.5 + 2*6*0.5 + 10*0.5 – 0 – 10*0.5 = 10 J.