Textbook Problem 4A1 part C

[Bronson Mathos 1H]

Hello, I am a bit confused on the reasoning of this question and I was wondering if someone could explain to me why in the question 4A1 part C, the system of a bomb calorimeter in which benzene is burned is considered an isolated system?

[Hayden Lee 1C]

A bomb calorimeter is considered to be an isolated system because no matter or heat can be exchanged with the surroundings. While the system within the calorimeter can release heat, it is not released to the surroundings.

[Bailey Giovanoli 1L]

To add on, you know that all energy that leaves the benzene will enter the calorimeter because it's isolated. Therefore, you know the heat absorbed by the calorimeter is equal and opposite of the benzene reaction because none goes outside the calorimeter.

[SashaAnand2J]

Hi Bronson,
A bomb calorimeter is considered an isolated system because neither energy nor matter is exchanged with its surroundings. However, there is no "perfectly" isolated system in nature, because over a long period of time, a bomb calorimeter may lose heat over time. As Dr. Lavelle mentioned in lecture, though, the universe can be considered a perfectly isolated system since change in internal energy is 0.