Question

20 J of heat is supplied to the system and work done on the system is 15 J. What is the change in internal energy of the system?

(a) 15 J

(b) 20 J

(c) 25 J

(d) 35 J

The question was asked in an international level competition.

This question is from Energy balance for Different type of systems topic in portion Miscellaneous of Chemical Process Calculation

Answer 1

Right option is (d) 35 J

The explanation is: For the given process ∆U = – (-W) +Q.