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sign of entropy

Posted: Mon Jan 29, 2018 4:26 pm
by Jack Papciak 2F
How do I know whether the entropy has a "+" or a "-"?

Re: sign of entropy

Posted: Mon Jan 29, 2018 4:29 pm
by Grace Boyd 2F
As Dr. Lavelle explained today in lecture, the sign of entropy depends on the direction of heat flow. If the system loses heat, the entropy will have a negative sign in front of it. If the surroundings gain heat, the entropy will have a positive sign. I hope this helps!

Re: sign of entropy

Posted: Mon Jan 29, 2018 6:00 pm
by Alyssa Pelak 1J
Additionally, entropy is positive when the reaction spontaneous. It means that the system has more possible states. Entropy is negative when the system has less possible states.

Re: sign of entropy

Posted: Mon Jan 29, 2018 7:45 pm
by Lauren Seidl 1D
Also, if delta entropy equals zero then the reaction is at equilibrium.

Re: sign of entropy

Posted: Wed Jan 31, 2018 4:26 am
by Leanne Wong 1H
You determine the sign of entropy by the direction of heat flow.

Re: sign of entropy

Posted: Wed Jan 31, 2018 8:43 am
by RohanGupta1G
Direction of heat flow determines the sign as well as whether or not the reaction is spontaneous.

Re: sign of entropy

Posted: Wed Jan 31, 2018 10:25 am
by Jingyi Li 2C
The sign of entropy indicates the direction of heat flow.

Re: sign of entropy

Posted: Wed Jan 31, 2018 3:59 pm
by Amanda Wu 2C
The sign of entropy is indicative of the heat flow in or out of the system. A system in which heat flows out to the surroundings will have a negative entropy whereas a system in which heat flows in from the surroundings will have a positive entropy.

Re: sign of entropy

Posted: Wed Jan 31, 2018 10:21 pm
by Josh Moy 1H
sign of entropy depends on flow of heat

Re: sign of entropy

Posted: Thu Feb 01, 2018 2:06 pm
by melissa carey 1f
Additionally, during a process of expansion entropy increases as there are more possible states.

Re: sign of entropy

Posted: Thu Feb 01, 2018 2:12 pm
by JamesAntonios 1E
Jack Papciak 2F wrote:How do I know whether the entropy has a "+" or a "-"?


It depends on the the ratio of final to initial temperature, volume, and/or pressure. You can logically think about by analyzing whether the number of microstates is increasing or decreasing, which can give an indication to what the sign should be.

Re: sign of entropy

Posted: Sun Feb 04, 2018 9:29 am
by Luke Bricca 1H
Additionally, in connection with Gibbs free energy, if the sign of the delta G is negative, the reaction is spontaneous and favorable.