Structure Edit
Solid acetic acid in, the molecules form pairs ( dimers ), being Connected by hydrogen bonds . [ 20 ] The dimers Can also be detected in the vapor at 120 ° C (248 ° F). Dimers also occur in the Liquid Phase in dilute hydrogen-bonding Solutions in non-solvents, and a certain extent in Pure acetic acid, [ 21 ] but are disrupted by hydrogen-bonding solvents. The dissociation enthalpy of the dimer is estimated at 65.0 to 66.0 kJ / mol, and the dissociation entropy at 154-157 J mol -1 K -1 . [ 22 ] Other carboxylic acids Lower dimerize in a similar Fashion. [ 23 ].