Knowledge Bank

The infrared spectra of formic, acetic, and propanoic acids in the liquid state have been studied in the 4000 to $100cm-1$ spectral region over a temperature range from near the freezing points to near $100\circ C$ for each of the samples. The Raman spectra have been studied in the 4000 to $150cm-1$ region over the same temperature ranges. The temperature behavior of the low frequency intermolecular band and those intramolecular bands affected by hydrogen bonding is more apparent in formic acid than in acetic or propanoic acids.