9.3

Volume:
Temperature:

Moderators: Chem_Mod, Chem_Admin

Gabriela Carrillo 1B
Posts: 53
Joined: Fri Sep 29, 2017 7:04 am

9.3

Postby Gabriela Carrillo 1B » Sun Jan 28, 2018 10:03 pm

Why is energy negative in the first calculation of entropy (-40000J/800K) and positive in the second (40000J/200K)?

Ashin_Jose_1H
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

Re: 9.3

Postby Ashin_Jose_1H » Sun Jan 28, 2018 10:10 pm

Heat is being transferred from one reservoir to another. In the first one, q is negative for heat is leaving the system. In the second one, q is positive for heat is being supplied to the system.

Rebecca Doan 2L
Posts: 51
Joined: Thu Jul 27, 2017 3:01 am

Re: 9.3

Postby Rebecca Doan 2L » Sun Jan 28, 2018 11:39 pm

when heat is exiting the system, heat is being lost so it is negative. When additional heat is entering a system, heat is being added, hence the positive sign.

Sophia Kim 1C
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 1 time

Re: 9.3

Postby Sophia Kim 1C » Sun Jan 28, 2018 11:42 pm

In the beginning the energy is negative because heat is leaving the system (making it negative) but when heat is added it to the system then it is positive

Patricia Macalalag 2E
Posts: 53
Joined: Sat Jul 22, 2017 3:00 am

Re: 9.3

Postby Patricia Macalalag 2E » Tue Jan 30, 2018 11:36 pm

The signs dictate the flow of energy

Meredith Steinberg 2E
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

Re: 9.3

Postby Meredith Steinberg 2E » Wed Jan 31, 2018 11:26 am

When heat is leaving a system, it's energy sign is negative. When it is entering a system, its energy sign is positive. This can also be applied when you're doing problem 9.5 when heat is being transferred from one reservoir to another.


Return to “Entropy Changes Due to Changes in Volume and Temperature”

Who is online

Users browsing this forum: No registered users and 1 guest