Question

For an open unsteady state system, 15 J of heat was supplied and -5 J of work was done on the system, what is the value of a change in enthalpy?

(a) 10 J

(b) – 15 J

(c) 20 J

(d) – 25 J

I have been asked this question in an interview for internship.

I need to ask this question from Vaporization and Energy Balances for Open, Unsteady-State Systems topic in division Introduction to Energy Balances for Processes without Reaction and Calculation of Enthalpy Changes of Basic Chemical Engineering

Answer 1

Correct answer is (a) 10 J

Explanation: ∆H = 15 – 5 = 10 J.