## System vs Surroundings

Milena Aragon 2B
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### System vs Surroundings

I have a hard time determining what the system is in a reaction. Is there a way of easily identifying what it is or do we have to memorize that for certain examples one is the system and thus the other is the surroundings?

Nathan Tran 4K
Posts: 92
Joined: Fri Sep 28, 2018 12:16 am

### Re: System vs Surroundings

Usually, the system is the actual thing we are dealing with in the question. For example, if we are looking at the piston and identifying characteristics like work, heat, etc., the piston is the system, while the surroundings is what is supplying heat or what the system is losing heat to or the surroundings is what does work on the piston or what the piston is doing work on. I would say it is usually very easy to identify what is the system based off the question if it is not already explicitly identified.

Jonathan Zhao 4H
Posts: 57
Joined: Fri Sep 28, 2018 12:26 am

### Re: System vs Surroundings

Yes, the system vs. surrounding should not be something you have to memorize. As mentioned before, the system is simply the situation in question, such as a piston. Since the first law of thermodynamics states the conservation of energy, a change in energy of the system means a resultant change in surroundings to balance it out.

Posts: 35
Joined: Fri Sep 28, 2018 12:19 am

### Re: System vs Surroundings

System vs. surrounding should be evident depending on the question that is given. It usually just determines whether a certain value is positive or negative in relation to the system at hand. For example, if the question states the surroundings gained x amount of energy, then energy left the system, so the energy change of the system would have to be negative while the surroundings would have a positive value in energy change.

Fanny Lee 2K
Posts: 73
Joined: Fri Sep 28, 2018 12:29 am

### Re: System vs Surroundings

Simply, the system is the object you are observing and the surrounding is everything else.

Yiting_Gong_4L
Posts: 69
Joined: Fri Sep 28, 2018 12:25 am

### Re: System vs Surroundings

system is the object, and surrounding is everything around it that can apply heat to it or lose heat.

Tony Chung 2I
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: System vs Surroundings

The system is the thing that you're observing/looking at, while the surrounding is everything else.

Brian Chang 2H
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

### Re: System vs Surroundings

The system is the "reaction" that you're observing, typically in a piston or some form of enclosed chamber. (Unless it's an open system)

The surroundings are just everything else.