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Topic: cyclic entropy  (Read 3401 times)

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Offline app23yy

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cyclic entropy
« on: September 22, 2009, 01:54:43 PM »
hey guys, I'm doing a homework, and this problem is giving me headache. Can you help me solve it? Thanks,

Consider the following cycle using 1 mole of an ideal gas, initially at 25 C and 1 atm pressure.
Step1. Isothermal expansion against zero pressure to double the volume( Joule Expansion).
Step2. Isothermal, reversible compression from 1/2 atm to 1 atm.

a) Calculate the value of cyclic dq/T and note that the sign conforms with cyclic dq(irr)/T<0. Calculate delta S for step 2. Realizing that for the cycle, delta S(cycle)=0. Find delta S for step 1.

b) Show that delta S for step 1 is not equal to the q for step 1 divided by T.
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Offline MrTeo

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Re: cyclic entropy
« Reply #1 on: September 22, 2009, 03:13:28 PM »
Quote from: app23yy on September 22, 2009, 01:54:43 PM
hey guys, I'm doing a homework, and this problem is giving me headache.

Take an aspirin and show us your attempts. Seriously  ;)
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The way of the superior man may be compared to what takes place in traveling, when to go to a distance we must first traverse the space that is near, and in ascending a height, when we must begin from the lower ground. (Confucius)

Offline renge ishyo

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Re: cyclic entropy
« Reply #2 on: September 22, 2009, 04:18:42 PM »
Quote
Take an aspirin and show us your attempts.

loL! That was a Borek reply + 1
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