EXCESS MOLAR ENTHALPIES OF N-ALKANOLS OR ISOMERIC ALKANOLS PLUS N,N-DIMETHYLETHANOLAMINE AT 298.15 K

Excess molar enthalpies H-E measured at 298.15 K with a Picker flow mi crocalorimeter are reported for methanol+, ethanol+, n-propanol+, n-bu tanol+, n-pentanol+, n-hexanol+, iso-propanol+, iso-butanol+, sec-buta nol+ and tert-butanol+ N, N-dimethylethanolamine. The experimental res ults have shown that for the binary mixtures containing one of the n-a lkanols (C-1-C-6), excess molar enthalpies are all negative over the e ntire composition range and increase with lengthening of the alkyl cha in of the alkanol. For the mixtures containing an isomeric alkanol, ex cess molar enthalpies for each isomeric butanol are negative, but for iso-propanol H-E values are positive except for the mixtures approachi ng the pure alkanol. Based on our experimental results, a brief discus sion is given in terms of molecular interactions.