Vapour Pressures of some Mon- and Di-Alkyl Substituted Aliphatic Amides at Different Temperatures

Vapour pressures of N-methylacetamide, N-methyl-propionamide, N, N-dimethylformamide, N, N-dimethylacetamide, and N, N-diethylformamide, have been determined in the temperature range 30- 90°C. The values of the heats of vaporization, obtained from the v.p. data, appear to be larger for the mono-substituted compounds than those for the di-substituted ones. The vapour pressures of the former are also lower. These facts confirm a stronger molecular interaction in the mono-substituted amides