8.1 (6th Edition)

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8.1 (6th Edition)

Postby melodyzaki2E » Thu Jan 31, 2019 10:45 pm

Identify the following systems as open, closed, or isolated:
(a) coffee in a very-high-quality thermos bottle; (b) coolant in
a refrigerator coil; (c) a bomb calorimeter in which benzene
is burned; (d) gasoline burning in an automobile engine;
(e) mercury in a thermometer; (f) a living plant.

Does anyone have any tips on how to identify the different systems?

Ashley Zhu 1A
Posts: 69
Joined: Fri Sep 28, 2018 12:16 am

Re: 8.1 (6th Edition)

Postby Ashley Zhu 1A » Thu Jan 31, 2019 11:45 pm

open systems are usually exposed to the air and can exchange both matter and energy: in this case, the gas burning in a car engine (releases heat, which is part of energy and exhaust which contains matter) and a living plant (exchanges gases like O2 and CO2 which counts as matter) are open systems
closed systems are not able to exchange matter with their surroundings but are able to transfer energy: the coolant in a refrigerator coil (confined within the coil so can't exchange matter but gives off the heat it absorbs, which is why you feel warm "air" coming out of the fridge sometimes) and the mercury in a thermometer (confined w/in the thermometer but when heated, mercury expands and tells you the temperature on the thermometer scale) are both closed systems
isolated systems can't exchange matter or energy with their surroundings - an easy way to tell is if they're in a sealed vacuum: the coffee in a high quality thermos bottle (sealed off and doesn't lose heat by definition of what a thermos is) and the bomb calorimeter (look at bomb calorimeter in textbook) are both isolated systems

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