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Homework Help: Enthalpy change of an isothermal process

  1. Jan 16, 2010 #1
    what is the enthalpy change of an isothermal process?(Why is it 0?)
  2. jcsd
  3. Jan 16, 2010 #2
    delta H=delta U+work done on the system(PV work)
    For an isthermal expansion of a gas,delta U is 0.Since the gas expands,W is not zero.Then how can delta H be 0?
  4. Oct 9, 2011 #3
    Δ(pv) isn't pv work, as both pressure and volume are changing. its best to change this to nRΔT. Now its easy to see the because ΔT=0, Δ(pv) is also 0.
  5. Oct 10, 2011 #4

    Andrew Mason

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    It is 0 if you are dealing with an ideal gas but not necessarily for a real gas.

  6. Nov 18, 2012 #5
    delta H= nC(p)ΔT where C(p) is molar heat capacity at constant pressure. Since in isothermal process ΔT is zero. Thr4 enthalpy change is zero and the term 'pv' is not work. They are pressure and volume of system respectively...
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