Which process does more work?


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Eliza_Beglari_2L
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Which process does more work?

Postby Eliza_Beglari_2L » Fri Feb 10, 2017 9:44 pm

From Chapter 8 Number 11:
A piston confines 0.200 mol Ne(g) in 1.20 L at 25 degrees C. Two experiments are performed. (a) The gas is allowed to expand through an additional 1.20 L against a constant pressure of 1.00 atm (b) The gas is allowed to expand reversibly and isothermally to the same final volume. Which process does more work?

How do you know which equation to use to compare the two processes?

Jeffrey_Huang_2K
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Re: Which process does more work?

Postby Jeffrey_Huang_2K » Fri Feb 10, 2017 10:23 pm

You'll want to calculate the work done by each pathway.
Path A is done at constant pressure so use W=-P*DeltaV (irreversible pathway)
Path B is reversible expansion so use W=-nrT*ln(V2/V1) (reversible pathway)

Timothy_Yu_Dis3A
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Re: Which process does more work?

Postby Timothy_Yu_Dis3A » Sat Feb 11, 2017 12:07 am

The work calculated for a reversible and isothermal pathway is the maximum work possible, therefore it is always a higher value as compared to the work calculated for an irreversible pathway. Real life processes are irreversible, as not all heat is converted to work.

edward_qiao_3I
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Re: Which process does more work?

Postby edward_qiao_3I » Sat Feb 11, 2017 4:53 pm

So when a question is asking you to consider the difference between reversible or irreversible processes, how can you tell the difference?

AKatukota
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Re: Which process does more work?

Postby AKatukota » Thu Jan 30, 2020 10:12 pm

So for the first one, why does the volume remain 1.20L?

Connie Chen 1E
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Re: Which process does more work?

Postby Connie Chen 1E » Fri Jan 31, 2020 12:47 pm

AKatukota wrote:So for the first one, why does the volume remain 1.20L?

The volume doesn't remain 1.20L, it expands an additional 1.20L.


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