niobium

• Formula: Nb
• Molecular weight: 92.90638
• IUPAC Standard InChI: InChI=1S/Nb Copy

  
• IUPAC Standard InChIKey: GUCVJGMIXFAOAE-UHFFFAOYSA-N Copy
• 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:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • References
  • Notes
• Other data available:
  • Gas phase ion energetics data
  • Ion clustering data
• 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:
  • Switch to calorie-based units

Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, References, Notes

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

Gas Phase Heat Capacity (Shomate Equation)

C_p° = 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
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Condensed phase thermochemistry data

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

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

Liquid Phase Heat Capacity (Shomate Equation)

C_p° = 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
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Solid Phase Heat Capacity (Shomate Equation)

C_p° = 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
    C_p = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, 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.

Data compiled by: Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

 +  = ( • )

By formula: Nb⁺ + Nb = (Nb⁺ • Nb)

Enthalpy of reaction

( • 9) +  = ( • 10)

By formula: (Nb⁺ • 9Nb) + Nb = (Nb⁺ • 10Nb)

Enthalpy of reaction

( • 2) +  = ( • 3)

By formula: (Nb⁺ • 2Nb) + Nb = (Nb⁺ • 3Nb)

Enthalpy of reaction

( • 3) +  = ( • 4)

By formula: (Nb⁺ • 3Nb) + Nb = (Nb⁺ • 4Nb)

Enthalpy of reaction

( • 4) +  = ( • 5)

By formula: (Nb⁺ • 4Nb) + Nb = (Nb⁺ • 5Nb)

Enthalpy of reaction

( • 5) +  = ( • 6)

By formula: (Nb⁺ • 5Nb) + Nb = (Nb⁺ • 6Nb)

Enthalpy of reaction

( • 6) +  = ( • 7)

By formula: (Nb⁺ • 6Nb) + Nb = (Nb⁺ • 7Nb)

Enthalpy of reaction

( • 7) +  = ( • 8)

By formula: (Nb⁺ • 7Nb) + Nb = (Nb⁺ • 8Nb)

Enthalpy of reaction

( • 8) +  = ( • 9)

By formula: (Nb⁺ • 8Nb) + Nb = (Nb⁺ • 9Nb)

Enthalpy of reaction

( • ) +  = ( • 2)

By formula: (Nb⁺ • Nb) + Nb = (Nb⁺ • 2Nb)

Enthalpy of reaction

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction 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]

Loh, Lian, et al., 1988
Loh, S.K.; Lian, L.; Hales, D.A.; Armentrout, P.B., Collision - Induced Dissociation Processes of Nb4+ and Fe4+: Fission vs Evaporation, J. Chem. Phys., 1988, 89, 1, 610, https://doi.org/10.1063/1.455455 . [all data]

Armentrout and Kickel, 1994
Armentrout, P.B.; Kickel, B.L., Gas Phase Thermochemistry of Transition Metal Ligand Systems: Reassessment of Values and Periodic Trends, in Organometallic Ion Chemistry, B. S. Freiser, ed, 1994. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction 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
  T	Temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔrH°	Enthalpy of reaction 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.