THERMAL PRESSURE COEFFICIENT AND INTERNAL -PRESSURE FOR ALCOHOL LIQUIDS

The thermal pressure coefficients of liquids for 1-pentanol, 1-hexanol , 1-heptanol and 1-octanol have been measured over the temperature ran ge of 25 similar to 85 degrees C. It is found that their internal pres sures don't almost vary with temperature. The modified van der Waals m odel is applied to the alcohol liquids. As non-associating liquids, th eir excluded volume can also be expressed as a linear function of dens ity. However, the ratio of the model parameters, B/A(2) is not a const ant and decreases speedily with increase of the number of carbon atoms in the alcohol molecule. This ratio may be considered as a measure of the ability of self-association for alcohols.