Question

What is the heat transferred from 5 mole of the system if the output sensible heat is 1 J/mole, input sensible heat is 3 J/mole, and heat of solution is 4 J/mole?

(a) 0

(b) 5 J

(c) 10 J

(d) 20 J

I have been asked this question in an online interview.

My question comes from Effects of Mixing into Energy Balance topic in portion 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 (c) 10 J

Easiest explanation: Q = ∆Hout,sensible – ∆Hin,sensible + ∆Hsolution = 5*(1 – 3 + 4) = 10 J.