Molecule
Name
Acetic acid
IUPAC name
Acetic acid
Secondary names
Ethanoic acid, Methanecarboxylic acid, Ethylic acid, Vinegar acid, CH3COOH, CH3CO2H, C2H4O2, AcOH
InChI
InChI=1S/C2H4O2/c1-2(3)4/h1H3,(H,3,4)
InChI key
QTBSBXVTEAMEQO-UHFFFAOYSA-N
CAS number
64-19-7
Formula
CH3COOH
Chemical formula
CH3COOH
Structural formula
[CH3]C(=O)[OH]
Charge
0
Unpaired electrons
0
  Atom Name Number
C Carbon 2
H Hydrogen 4
O Oxygen 2
Relations
  • no
Isotope mixture type
terrestrial abundance
Spin type
equilibrated
Spin quantum numbers
1/2 (para, E), 3/2 (ortho, A)
Equilibrium ortho/para ratio
2 (2/1)
Molar mass
60.052 g/mol
State STP
liquid
Protic
protic
Polarity
polar
Dipole
1.7 D
Molecule symmetry
Cs
Case
nonlinear-polyatomic
Vibrations number
18
Vibrations
Label Mode Bond Symmetry Degeneracy Fundamental frequency Observed frequency Observed frequency Harmonic frequency Activity IR Activity Raman Strength Comments
V1 stretching OH A no 3583.0 3583.0 active inactive m
V2 stretching CH3 A double 3051.0 3051.0 active active vw degenerate with ν13
V3 stretching sym. CH3 A no 2944.0 2944.0 active inactive vw
V4 stretching >C=O A no 1788.0 1788.0 active inactive vs
V5 deformation CH3 A double 1430.0 1430.0 active inactive shoulder - degenerate with ν14
V6 bending sym. CH3 A no 1382.0 1382.0 active inactive m
V7 bending A_{}' no 1264.0 1264.0 active inactive m
V8 stretching \eqslantgtr C-O- A_{}' no 1182.0 1182.0 active inactive s
V9 bending asym. in-p (rocking) -C \leq H_3 A_{}' no 989.0 989.0 active inactive m
V10 stretching \eqslantgtr C-C\leq A_{}' no 847.0 847.0 active inactive w
V11 deformation O=C(-)-O- A_{}' no 657.0 657.0 active inactive s
V12 deformation \geq C-C(-)=O A_{}' no 581.0 581.0 active inactive m
V13 stretching -C \leq H_3 A double 2996.0 2996.0 active active vw degenerate with \nu_2
V14 deformation -C \leq H_3 A double 1430.0 1430.0 active inactive shoulder - degenerate with \nu_5
V15 bending asym. in-p (rocking) -C \leq H_3 A double 1048.0 active inactive w degenerate with \nu_5
V16 bending out-p >C=O A no 642.0 642.0 active inactive s
V17 deformation \eqslantgtr C-O- A no 534.0 534.0 active inactive m
V18 deformation -C \leq H_3 A no 93.0 active inactive czlculated frequency
Publications
Chemical functions
  Function Number
R-CH_3 1
R-C(=O)-OH 1
Chemical bonds
  Bond Number
\geq C-H 3
\eqslantgtr C-C\leq 1
>C=O 1
\eqslantgtr C-O- 1
-O-H 1