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Thermodynamics: Internal Energy and Enthalpy

  1. Apr 24, 2012 #1
    H = U+ pV
    pV = nRT

    H= U+ nRT

    H= H (T)

    I dont understand the transition from U+ nRT to H (T)

    Can someone explain this?

    I get that H = U + pV

    But how is H= U+ nR
  2. jcsd
  3. Apr 24, 2012 #2
    For a monoatomic ideal gas, U=(3/2) PV. Hence, H=(5/2) PV=(5/2) nRT
    Which shows that H for an ideal gas is a function of T alone ,i.e, H=H(T).
    Of course it is also function of n since it is extensive quantity. However, this dependence is easy to get rid of by defining h=H/n which is an intensive quantity.
  4. Apr 24, 2012 #3
    thank you...that clears it up!
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