Fugacity
A measure of the tendency of a gas to escape or expand. Fugacity (fi) is the pressure value
needed at a given temperature to make the properties of a non-ideal gas satisfy
the equation for an ideal gas, i.e.,
fi = Yi Pi
where Yi is the fugacity coefficient and Pi is the partial pressure for component i of the gas. For an ideal gas, Yi=1
The idea for defining fugacity comes from the equation for calculating the free energy change at a constant temperature for the ideal gas.
dG=VdP-SdT (The temperature is contstant so SdT=0)
Gpf=Gpi+∫ VdP (integrate from pi top f)
For an ideal gas
Gpf=Gpi+ RT∫ (1/P)dP
Gpf=Gpi+ RT*ln (pf/pi)
If pi=pº
G(p)=Gº+RT* ln (P/Pº) Gibbs Energy for ideal gas
G=Gº+RT*ln(ƒ/Pº)
ƒ=øPº
fi = Yi Pi
where Yi is the fugacity coefficient and Pi is the partial pressure for component i of the gas. For an ideal gas, Yi=1
The idea for defining fugacity comes from the equation for calculating the free energy change at a constant temperature for the ideal gas.
dG=VdP-SdT (The temperature is contstant so SdT=0)
Gpf=Gpi+∫ VdP (integrate from pi top f)
For an ideal gas
Gpf=Gpi+ RT∫ (1/P)dP
Gpf=Gpi+ RT*ln (pf/pi)
If pi=pº
G(p)=Gº+RT* ln (P/Pº) Gibbs Energy for ideal gas
G=Gº+RT*ln(ƒ/Pº)
ƒ=øPº
Aplications and examples.
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Resume.
Escape tendency of species. To flee from one phase to another.
Escape tendency of species. To flee from one phase to another.
Fugacity in mixtures.
References.
- Science World Wolfram. (n. d.) Fugacity. Retrieved from: http://scienceworld.wolfram.com/chemistry/Fugacity.html
- LearnChemE (2012). Fugacity Introduction. Retrieved from: https://youtu.be/fkqmf_QR4Yg
- LearnChemE (2012). Calculate fugacity of a fluid. Retrieved from:
http://youtu.be/ZqbdhF6422o
- LearnChemE (2011). Fugacity pf a single component. Retrieved from:
http://youtu.be/C4EDtrdojyM
- LearnChemE (2011). What is fugacity in a mixture? Retrieved from: http://youtu.be/OZFB48wVtjw
- Science World Wolfram. (n. d.) Fugacity. Retrieved from: http://scienceworld.wolfram.com/chemistry/Fugacity.html
- LearnChemE (2012). Fugacity Introduction. Retrieved from: https://youtu.be/fkqmf_QR4Yg
- LearnChemE (2012). Calculate fugacity of a fluid. Retrieved from:
http://youtu.be/ZqbdhF6422o
- LearnChemE (2011). Fugacity pf a single component. Retrieved from:
http://youtu.be/C4EDtrdojyM
- LearnChemE (2011). What is fugacity in a mixture? Retrieved from: http://youtu.be/OZFB48wVtjw