Question

What is the heat of reaction if enthalpy of inputs and outputs at 25^oC are 10 J and 20 J, the enthalpy of input and outputs at given temperature are 25 J and 30 J, enthalpy change of the reaction is 50 J?

(a) 45 J

(b) 50 J

(c) 55 J

(d) 60 J

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

This intriguing question comes from Energy Balances Application in Processes in division 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

The correct answer is (c) 55 J

Explanation: Heat of reaction = (25 – 10) – (30 – 20) + 50 = 55 J.