An isolated system consists of a block of ice floating in a glass of water. The ice melts completely at constant temperature. Which of the following identifies the change in internal energy of the system and the change in entropy of the system?

A

There were a number of comments on this question from the teachers. In this situation the slight change in volume of the water/ice can be taken as negligible and it must be assumed that the water is not at 0^oC, otherwise no melting would occur. The statistics showed that the better candidates understood this, choosing A as the best response.