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Homework Help: Entropy chance with a carnot cycle?

  1. Jul 29, 2010 #1
    in a carnot cycle the gas expands adiabatically from 200 degrees to 500 degrees. what is the efficecy? and what is the entropy change of the gas during the expansion?

    sorry - i got the efficiency to be: 38.8%

    however I am unsure how to work out the entropy chance? any hints???
  2. jcsd
  3. Jul 29, 2010 #2
    however my thinking is that if the the system is adiabatic... then the entropy will stay constant.... then it will be 0??? am i on the right lines? thanks
  4. Jul 30, 2010 #3
    Hi I am still struggling with this. any advice? thanks
  5. Jul 30, 2010 #4


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    If ΔS=dQ/T and dQ=0 for an adiabatic process then ΔS=0. So you are right.
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