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Change in GIbbs free energy for ethanol

  1. May 7, 2005 #1
    hey i seem to be having a lot of trouble with this type of question:
    Calculate the change in Gibbs energy of 35g of ethanol (mass density = 0.789g cm-3) when the pressure is increased isothermally from 1 atm to 3000 atm.

    in my notes i have that dG=V(Pf-Pi) and search up on the net that mass=volume*density so volume of ethanol comes to 35/.789 the answer is suppose to be 10.4kJ but i get nowhere near it.

    dG=(35/.789)*(3000-1) is this the right equation because thats all i can find
    pls help me! thanks
  2. jcsd
  3. May 7, 2005 #2


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    [tex] \Delta G=V\Delta p [/tex]

    sounds right.I'm sure you need to convert all units into SI-mKgs.

    1 atm=101,325 Pa
    1 cm^{3}=10^{-6}m^{3}


  4. May 7, 2005 #3
    thanks man

    Thanks heeeeeeeeeaps! Daniel :biggrin:
    you made my day. spent ages doing that Q like hours and hours just seraching what i was doing wrong. thanks again.
    this forum rOcks!!
  5. May 7, 2005 #4


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    Please,do not double post.You should have asked it in one single forum.I think Classical Physics was the appropiate choice...

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