Chemical Thermodynamics Joule-Thompson Expansion Joule-Thompson - - PowerPoint PPT Presentation

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Oct 31, 2022 388 likes •493 views

Chemical Thermodynamics Joule-Thompson Expansion Joule-Thompson expansion depends on non-ideal characteristics of gases. Compare NH 3 and He in a Joule-Thompson expansion for P 1 =100 bar to P 2 =1 bar at an initial temperature of 260

SLIDE 1

Chemical Thermodynamics

SLIDE 2

Joule-Thompson Expansion

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Joule-Thompson expansion depends on non-ideal characteristics of gases.

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Compare NH3 and He in a Joule-Thompson expansion for P1=100 bar to P2=1 bar at an initial temperature of 260 K.

CEM 484 Chemical Thermodynamics 2

SLIDE 3

Joule-Thompson Expansion

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Continue comparison between NH3 and He.

CEM 484 Chemical Thermodynamics 3

SLIDE 4

Joule-Thompson Expansion

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Difference between NH3 and He due to differences in intermolecular forces.

CEM 484 Chemical Thermodynamics 4

SLIDE 5

Joule-Thompson Expansion

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Continuously repeating a Joule-Thompson expansion is the basis for a refrigerator

CEM 484 Chemical Thermodynamics 5

SLIDE 6

Ideal coolant

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Look at intermolecular forces to determine an ideal refrigerant.

CEM 484 Chemical Thermodynamics 6

SLIDE 7

Cp/Cv

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Most chemistry done at constant pressure (so Cp is typically tabulate) but most equations involve Cv.

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Convert between Cp and Cv.

CEM 484 Chemical Thermodynamics 7

SLIDE 8

Cp/Cv

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Relationship between Cp and Cv dependent on equation of state.

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For an ideal gas:

CEM 484 Chemical Thermodynamics 8

SLIDE 9

Cp/Cv

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For a solid block of iron:

CEM 484 Chemical Thermodynamics 9