Excess volumes of 1-alcohol plus heptane mixtures at 298.15 and 388.15 K -Application of an association model with flory interaction term

The excess volumes of 1-pentanol +, 1-hexanol +, 1-heptanol +, 1-octanol +, 1-decanol + and 1-dodecanol + heptane mixtures were evaluated at 298.15 an d 308.15 K from the density data. The excess volumes were found to decrease with the increase in the carbon chain length of alcohol molecules. The tem perature coefficient for the excess volumes was also observed to show a dec reasing trend from 1-pentanol + to 1-dodecanol + heptane mixtures. The exce ss volumes were also calculated by combining the individual physical and ch emical contributions, evaluated by combining an association model with Flor y's free Volume theory. Reasonable agreement between the experimental and c alculated excess volumes for all the mixtures at 298.15 and 308.15 K was no ted.