Is Delta Enthalpy Zero for an Isothermal Gas Expansion Process?

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SUMMARY

In an isothermal gas expansion process, the change in enthalpy (delta H) is not zero. While the change in internal energy (delta U) is zero, the work done during the expansion is given by the equation nC ln(V2/V1). The correct relationship is delta H = delta U + delta(PV), where delta(PV) is zero for an ideal gas under constant temperature and number of moles. Therefore, delta H is not equal to zero, contradicting some textbook assertions.

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Is delta enthalpy zero for...

Is delta H, for an isothermal process in which a gas expands?
delta H=delta U+work done,correct?
delta U is 0,but work done = nCln(V2/V1).
So,delta H is not equal to 0.But my book says so.
 
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sachin123 said:
delta H=delta U+work done,correct?
.

No. deltaH = deltaU + delta(PV). Work done is p delta(V) (under conditions of constant pressure).

For an ideal gas delta(PV) = R delta(nT). As long as the number of gas molecules in the system (n) and the temperature (T) remain constant, delta(PV) = 0.
 

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