Problem 8.1 (c) 6th edition

[Maya_Peterson1C]

Why is "coolant in a refrigerator coil" considered an isolated system? I am not familiar with the contraptions inside a refrigerator, so I am just wondering.

[David Effio 1H]

As far as I know, the coolant in a refrigeration coil does not absorb or release heat or matter. It simply changes its internal temperature to do all the necessary cooling via changes in the pressure within the coil. I found this link with the inner workings of a refrigerator which I hope does a better job at explaining it than I could, but basically, it's the same old idea that the coolant itself neither leaves the coil or changes it temperature by exchanging heat with the outside.

https://www.explainthatstuff.com/refrigerator.html

[Fionna Shue 4L]

Coolant un a refrigerator coil is actually a closed system, not an isolated system.