Question

25 J of heat is supplied to a system and work done by the system is 10 J. What is the change in internal energy of the system?

(a) 10 J

(b) 15 J

(c) 25 J

(d) 35 J

I have been asked this question during an interview.

This intriguing question originated from Energy balance for Different type of systems topic in chapter Miscellaneous of Chemical Process Calculation

Answer 1

The correct option is (b) 15 J

To explain I would say: For the given process ∆U = -W +Q.