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Thermodynamics: Internal Energy and Enthalpy

by leah3000
Tags: enthalpy, internal energy
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Apr24-12, 12:28 AM
P: 43
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
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Useful nucleus
Apr24-12, 02:14 AM
Useful nucleus's Avatar
P: 261
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.
Apr24-12, 10:12 PM
P: 43
thank you...that clears it up!

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