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
- Options:
Condensed phase thermochemistry data
Go To: Top, 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 | 7.087 | kcal/mol | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid,1 bar | 11.30 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in December, 1973 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid | 8.717 | cal/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 (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
| Temperature (K) | 2750. - 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 |
| 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 (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
| Temperature (K) | 298. - 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 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in December, 1973 |
References
Go To: Top, 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, Condensed phase thermochemistry data, References
- Symbols used in this document:
S°liquid,1 bar Entropy of liquid at standard conditions (1 bar) S°solid Entropy of solid at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.