PROBLEM: Some warm water is mixed with ice and the ice melts. Assume that the entire process happens in an insulated box. Does the internal energy of the combined (ice+water) system change? Does the entropy of the combined system change? Considering that the ice and water as separate system, discuss the change in internal energy and in entropy for each. ATTEMPT: I know that internal energy is dependent of change in temperature, there is a change in internal energy. So in this case, I am assuming, it is an isobaric process so the volume is changing. So there is a change in entropy. Separate systems: also change in internal energy. Again, change in entropy. There is something definitely wrong with my answer. WHAT IS IT?! I'm going crazy!