Systems

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Caroline C 1G
Posts: 53
Joined: Fri Sep 29, 2017 7:05 am

Systems

Postby Caroline C 1G » Wed Jan 10, 2018 8:39 pm

I'm a little confused regarding the classification of systems. What is the difference between an open, closed, and isolated system, and what are some examples of each?

Andrea ORiordan 1L
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Joined: Fri Sep 29, 2017 7:04 am
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Re: Systems

Postby Andrea ORiordan 1L » Wed Jan 10, 2018 8:49 pm

In discussing systems, we must discuss both the system itself and its relationship with its surroundings.

An open system is characterized by its ability to exchange matter and energy with its surroundings.
A closed system is characterized by its ability to exchange energy with its surroundings.
An isolated system can exchange neither energy nor matter with its surroundings.

Examples of an open system could include a pot of boiling soup without a lid or an open beaker.
Examples of closed systems include mercury thermometers and refrigerator coils.
An example of an isolated system is an insulated thermos.

Nancy Dinh 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:07 am

Re: Systems

Postby Nancy Dinh 2J » Wed Jan 10, 2018 8:52 pm

Open system - matter in a system are free to interact with the surrounding environment. Ex: Breathing in and out air
Closed system - matter in a system is separated from matter in the environment but heat/energy can still be exchanged. Ex: Closed water bottle.
Isolated system - neither matter nor energy in a system can be exchanged with the environment. Ex: A thermos

Amanda Wu 2C
Posts: 31
Joined: Sat Jul 22, 2017 3:00 am

Re: Systems

Postby Amanda Wu 2C » Wed Jan 10, 2018 9:14 pm

The classification of systems as open, closed, or isolated depend on whether they are able to permit exchanges of energy and/or matter between the system itself and its surroundings. For example, in an open system such as a lidless pot of boiling water set on a stovetop burner, there is both an exchange of energy and an exchange of matter between the system and its surroundings. Specifically, energy is transferred into the system from the surroundings via the burner to the pot; matter escapes the system (pot) into the surroundings as the boiling water vaporizes into the air because it's not contained by a lid. In a closed system such as a pot of boiling water, covered with a lid and set on a stovetop burner, only the exchange of energy between the system and its surroundings is permitted (via burner transferring energy to the pot); a transfer of matter is prohibited because the matter (water vapor) is contained in the system (pot) by the lid and prevented from escaping into the surrounding air. In an isolated system, such as a thermos with a lid and insulated walls that ideally prevent any energy transfer between its contents and the surroundings, the lid prevents any matter from escaping the system while (ideally) the insulated walls are adiabatic, meaning they don't allow the heat energy to enter or leave the system (thermos).


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