niobium


Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Quantity Value Units Method Reference Comment
Δfgas175.20kcal/molReviewChase, 1998Data last reviewed in December, 1973
Quantity Value Units Method Reference Comment
gas,1 bar44.524cal/mol*KReviewChase, 1998Data last reviewed in December, 1973

Gas Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 5131. to 6000.
A -3498.327
B 1228.910
C -161.4106
D 7.539436
E 11390.30
F 10163.38
G 1480.418
H 175.2000
ReferenceChase, 1998
Comment Data last reviewed in December, 1973

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Quantity Value Units Method Reference Comment
Δfliquid7.087kcal/molReviewChase, 1998Data last reviewed in December, 1973
Quantity Value Units Method Reference Comment
liquid,1 bar11.30cal/mol*KReviewChase, 1998Data last reviewed in December, 1973
Quantity Value Units Method Reference Comment
solid8.717cal/mol*KReviewChase, 1998Data last reviewed in December, 1973

Liquid Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 2750. to 5130.824
A 8.000001
B 0.000001
C -1.163347×10-8
D -1.085402×10-8
E 0.000014
F 2.835995
G 18.34025
H 7.085732
ReferenceChase, 1998
Comment Data last reviewed in December, 1973

Solid Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (cal/mol*K)
    H° = standard enthalpy (kcal/mol)
    S° = standard entropy (cal/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 298. to 2750.
A 5.261544
B 2.363327
C -1.350032
D 0.420576
E 0.005220
F -1.644573
G 14.46558
H 0.000000
ReferenceChase, 1998
Comment Data last reviewed in December, 1973

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References