niobium
- Formula: Nb
- Molecular weight: 92.90638
- IUPAC Standard InChI: InChI=1S/Nb
- IUPAC Standard InChIKey: GUCVJGMIXFAOAE-UHFFFAOYSA-N
- CAS Registry Number: 7440-03-1
- Chemical structure:
This structure is also available as a 2d Mol file - Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- NIST Atomic Spectra Database - Lines Holdings (on physics web site)
- NIST Atomic Spectra Database - Levels Holdings (on physics web site)
- NIST Atomic Spectra Database - Ground states and ionization energies (on physics web site)
- Gas Phase Kinetics Database
- X-ray Photoelectron Spectroscopy Database, version 5.0
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Gas phase thermochemistry data
Go To: Top, Condensed 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 |
|---|---|---|---|---|---|
| ΔfH°gas | 733.04 | kJ/mol | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 186.29 | J/mol*K | Review | Chase, 1998 | Data 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 (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 5131. to 6000. |
|---|---|
| A | -14637.00 |
| B | 5141.760 |
| C | -675.3420 |
| D | 31.54500 |
| E | 47657.00 |
| F | 42523.60 |
| G | 6194.070 |
| H | 733.0370 |
| Reference | Chase, 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 |
|---|---|---|---|---|---|
| ΔfH°liquid | 29.65 | kJ/mol | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid,1 bar | 47.30 | J/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid | 36.47 | J/mol*K | Review | Chase, 1998 | Data 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 (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 2750. to 5130.824 |
|---|---|
| A | 33.47200 |
| B | 0.000005 |
| C | -4.867440×10-8 |
| D | -4.541321×10-8 |
| E | 0.000058 |
| F | 11.86580 |
| G | 76.73560 |
| H | 29.64670 |
| Reference | Chase, 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 (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 298. to 2750. |
|---|---|
| A | 22.01430 |
| B | 9.888160 |
| C | -5.648530 |
| D | 1.759691 |
| E | 0.021839 |
| F | -6.880890 |
| G | 60.52400 |
| H | 0.000000 |
| Reference | Chase, 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
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) S°liquid,1 bar Entropy of liquid at standard conditions (1 bar) S°solid Entropy of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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