thermodynamics mcq

Question

A gas undergoes an isobaric expansion, meaning that the pressure remains constant during the process. The initial volume of the gas is 10 L, the final volume is 20 L, and the work done by the gas is 500 J. What is the change in internal energy of the gas?

a) -500 J b) 0 J c) 500 J d) Cannot be determined without more information

Answer 1

To solve this problem, we can use the equation: ΔU = q + w, where ΔU is the change in internal energy, q is the heat added or removed, and w is the work done on or by the system. In this case, we are given that the gas does 200 J of work on its surroundings, so w = -200 J. Plugging this into the equation above, we get: ΔU = q + (-200 J). We are not given the value of q, so we cannot determine the value of ΔU without more information. Therefore, the correct answer is (d), Cannot be determined without more information