Molecule
Name
Water
IUPAC name
Water, Oxidane
Secondary names
Hydrogen oxide, Dihydrogen oxide, H2O
InChI
InChI=1S/H2O/h1H2
InChI key
XLYOFNOQVPJJNP-UHFFFAOYSA-N
CAS number
7732-18-5
Comments
natural $H_2O$
Structure and atomic composition
Formula
$H_2O$
Chemical formula
H2O
Structural formula
[OH2]
Charge
0
Unpaired electrons
0
  Atom Name Number
$H$ Hydrogen 2
$O$ Oxygen 1
Relations
  • no
Isotope mixture type
terrestrial abundance
Isotopes
  Isotope Mole fraction
$H_2~^{16}O$ 0.9973406
$H_2~^{17}O$ 0.0003799
$H_2~^{18}O$ 0.0020495
$HD^{16}O$ 0.0002294
Spin type
equilibrated
Spin quantum numbers
0, 1
Molar mass
18.01528643 $g/mol$
State STP
liquid
Protic
protic
Polarity
polar
Dipole
1.855 $D$
Molecule symmetry
C2v
Case
nonlinear-triatomic
Vibrations number
3
Vibrations
Label Mode Bond Symmetry Degeneracy Fundamental frequency Observed frequency Observed frequency Harmonic frequency Activity IR Activity Raman Strength Comments
V1 stretching sym. $H_2O$ $A_{1}$ no 3657.0 3656.65 3835.0 active active s Raman: 3654 $cm^{-1}$ (gas)
V2 bending $H_2O$ $A_{1}$ no 1595.0 1594.59 1648.0 active active vs
V3 stretching asym. $H_2O$ $B_{1}$ no 3756.0 3755.79 3939.0 active active vs
Comments
vibration of the main isotope: $H_2^{16}O$. Data from NIST Chemistry WebBook
Publications
Chemical functions
  Function Number
$R-OH$ 2
Chemical bonds
  Bond Number
$-O-H$ 2