Isobaric Process - Entropy in Terms of Pressure and Volume Formula |
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| \( S \;=\; \Delta S \cdot ( - n \cdot R ) \cdot \left( n \cdot \dfrac{ p_f }{ p_i } \right) \) | ||
| Symbol | English | Metric |
| \( S \) = Entropy | \(Btu \;/\; lbm-R\) | \(kJ \;/\;kg-K\) |
| \( \Delta S \) = Entropy Change | \(Btu \;/\; lbm-R\) | \(kJ \;/\;kg-K\) |
| \( n \) = Number of Moles | \(dimensionless\) | \(dimensionless\) |
| \( R \) = Molar Gas Constant | \(lbf-ft \;/\; lbmol-R\) | \(J \;/\; kmol-K\) |
| \( ln \) = Natural Logarithm | \(dimensionless\) | \(dimensionless\) |
| \( p_f \) = Final Pressure | \(lbf \;/\; in^2\) | \(Pa\) |
| \( p_i \) = Initial Pressure | \(lbf \;/\; in^2\) | \(Pa\) |
Isobaric process is a thermodynamic process where the pressure is kept constant, \(\Delta p = 0\).
Isobaric Process - Entropy in Terms of Pressure and Volume Formula |
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| \( S \;=\; \Delta S \cdot ( n \cdot R ) \cdot \left( ln \cdot \dfrac{ V_f }{ V_i } \right) \) | ||
| Symbol | English | Metric |
| \( S \) = Entropy | \(Btu \;/\; lbm-R\) | \(kJ \;/\;kg-K\) |
| \( \Delta S \) = Entropy Change | \(Btu \;/\; lbm-R\) | \(kJ \;/\;kg-K\) |
| \( n \) = Number of Moles | \(dimensionless\) | \(dimensionless\) |
| \( R \) = Molar Gas Constant | \(lbf-ft \;/\; lbmol-R\) | \(J \;/\; kmol-K\) |
| \( ln \) = Natural Logarithm | \(dimensionless\) | \(dimensionless\) |
| \( V_f \) = Final Volume | \(in^3\) | \(mm^3\) |
| \(V_i \) = Initial Volume | \(in^3\) | \(mm^3\) |
