Ideal gas Helmholtz energy function: Difference between revisions

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From equations  
From equations  
:<math>Q_{NVT}=\frac{1}{N!} \left( \frac{V}{\Lambda^{3}}\right)^N</math>
:<math>Q_{NVT}=\frac{1}{N!} \left( \frac{V}{\Lambda^{3}}\right)^N</math>
and  
for the [[ Ideal gas partition function | canonical ensemble partition function for an ideal gas]], and  
:<math>\left.A\right.=-k_B T \ln Q_{NVT}</math>
:<math>\left.A\right.=-k_B T \ln Q_{NVT}</math>
one has
for the [[Helmholtz energy function]], one has
:<math>A=-k_BT\left(\ln \frac{1}{N!} + N\ln\frac{V}{\Lambda^{3}}\right)</math>
:<math>A=-k_BT\left(\ln \frac{1}{N!} + N\ln\frac{V}{\Lambda^{3}}\right)</math>
::<math>=-k_BT\left(-\ln N! + N\ln\frac{VN}{\Lambda^3N}\right)</math>
::<math>=-k_BT\left(-\ln N! + N\ln\frac{VN}{\Lambda^3N}\right)</math>

Revision as of 17:44, 8 June 2007

From equations

for the canonical ensemble partition function for an ideal gas, and

for the Helmholtz energy function, one has

Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle =-k_{B}T\left(-\ln N!+N\ln {\frac {N}{\Lambda ^{3}\rho }}\right)}

using Stirling's approximation

Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle =-k_{B}T\left(-N\ln N+N+N\ln N-N\ln \Lambda ^{3}\rho \right)}

one arrives at