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II.A.1. (XV.A.)

Listing of experimental data for HBr (hydrogen bromide)

Other names
Bromwasserstoff; Hydrobromic acid; hydrogen bromide;
InChI=1/BrH/h1H Br hydrogen bromide
State Conformation
1Σ C*V
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
Hfg(298.15K) enthalpy of formation -36.29 0.16 kJ mol-1 CODATA
Hfg(0K) enthalpy of formation -28.44 0.16 kJ mol-1 CODATA
Entropy (298.15K) entropy 198.59 0.00 J K-1 mol-1 CODATA
Integrated Heat Capacity (0 to 298.15K) integrated heat capacity 8.65 0.00 kJ mol-1 CODATA
Heat Capacity (298.15K) heat capacity 29.14   J K-1 mol-1 Gurvich
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency (cm-1) Frequency Reference Intensity (km mol-1) Int. unc. Intensity Reference Comment
1 Σ 2649 webbook       omega e

vibrational zero-point energy: 1324.5 cm-1
Calculated vibrational frequencies for HBr (hydrogen bromide).
More spectroscopic constants are available at the NIST Physics Laboratory website:
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
  8.46488   webbook Be

Calculated rotational constants for HBr (hydrogen bromide).

Product of moments of inertia moments of inertia
1.991479amu Å2   3.30698E-40gm cm2

Geometric Data
picture of hydrogen bromide

Point Group C∞v

Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees
Description Value unc. Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rHBr 1.414 0.000 1 2 NISTdiatomic re Br(81)

Atom x (Å) y (Å) z (Å)
H1 0.0000 0.0000 0.0000
Br2 0.0000 0.0000 1.4144

Atom - Atom Distances bond lengths
Distances in Å
  H1 Br2
H1   1.4144
Br2 1.4144  

Calculated geometries for HBr (hydrogen bromide).

Bond descriptions
Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-Br 1

Atom 1 Atom 2
H1 Br2

Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1Σ

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
11.680 0.030     webbook

Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
Dipole (Debye) Reference comment
0.827 NISTdiatomic  

Calculated electric dipole moments for HBr (hydrogen bromide).
Electric quadrupole moment quadrupole
Calculated electric quadrupole moments for HBr (hydrogen bromide).

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squib reference DOI
CODATA Cox, J.D.; Wagman, D.D.; Medvedev, V.A.CODATA Key Values for Thermodynamics. Hemisphere, New York, 1989  
Gurvich Gurvich, L.V.; Veyts, I. V.; Alcock, C. B., Thermodynamic Properties of Individual Substances, Fouth Edition, Hemisphere Pub. Co., New York, 1989 10.1351/pac198961061027
NISTdiatomic NIST Diatomic Spectral Database (  
webbook NIST Chemistry Webbook (  

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