State Properites

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Nahelly Alfaro-2C
Posts: 59
Joined: Wed Nov 15, 2017 3:04 am

State Properites

Postby Nahelly Alfaro-2C » Sun Jan 27, 2019 9:20 pm

Why are work and heat not considered a state property?

megansardina2G
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Joined: Fri Sep 28, 2018 12:23 am
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Re: State Properites

Postby megansardina2G » Sun Jan 27, 2019 9:25 pm

State properties are quantities that are independent of how a substance was prepared. Work is dependent on path, so it is not a state function. Since work is not a state property/function, heat cannot be either, since the first law of thermodynamics states that the change in the initial energy of a system is equal to the sum of heat and work transferred between the system and surrounding areas.

705192887
Posts: 77
Joined: Fri Sep 28, 2018 12:18 am

Re: State Properites

Postby 705192887 » Sun Jan 27, 2019 9:28 pm

They are not considered state properties because their value depends on the path taken from the initial to final values. State properties do not depend on the path taken, such as pressure or temperature.

RachelCheung1A
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Joined: Fri Sep 28, 2018 12:19 am

Re: State Properites

Postby RachelCheung1A » Sun Jan 27, 2019 9:30 pm

State properties do not depend on the path taken; they depend on the state of the substance. Work and heat are not considered because they take into account the path taken. Ex. In work, the formula is force times distance. If you have two molecules at the same starting point, molecule A that reaches point x in a straight line and molecule B that reaches point x in a exaggerated zigzag pattern, then although they both reach the same end point, their distances are different and therefore will have different values for work.

Tinisha 1G
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Joined: Fri Sep 28, 2018 12:17 am

Re: State Properites

Postby Tinisha 1G » Mon Jan 28, 2019 12:30 pm

State properties do not depend on the path taken. For example, for work, it depends on the distance traveled. A system that takes a shorter path will have performed less work than a system that a system that took a longer path. The final value is dependent on how the system was carried out.

George Ghaly 2L
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Re: State Properites

Postby George Ghaly 2L » Tue Jan 29, 2019 7:57 pm

State properties do not depend on the path that is taken to achieve the current state while properties such as work and heat do depend on which pathway is taken.

Megan_Ervin_1F
Posts: 78
Joined: Fri Sep 28, 2018 12:18 am

Re: State Properites

Postby Megan_Ervin_1F » Wed Jan 30, 2019 1:32 pm

I think Lavelle explained this concept well with the analogy of a mountain and hikers. If one group of hikers took a steep path to reach the top of the mountain and another group took a leisure path to the top of the mountain both groups have ended up at the same spot regardless of which path was taken.

Hannah Pham 1D
Posts: 62
Joined: Fri Sep 28, 2018 12:19 am

Re: State Properites

Postby Hannah Pham 1D » Wed Jan 30, 2019 11:56 pm

When dealing with work and heat, you have to take into account every step in the process of the change, not just the final and initial values.


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