Heat Capacities of Ionic Liquids as a Function of Temperature at 0.1 MPa. Measurement and Prediction

Heat capacities of nine ionic liquids were measured from (293 to
358) K by using a heat flux differential scanning calorimeter. The
impact of impurities (water and chloride content) in the ionic liquid
was analyzed to estimate the overall uncertainty. The Joback method
for predicting ideal gas heat capacities has been extended to ionic
liquids by the generation of contribution parameters for three new
groups. The principle of corresponding states has been employed to
enable the subsequent calculation of liquid heat capacities for ionic
liquids, based on critical properties predicted using the modified
Lydersen−Joback−Reid method, as a function of the temperature
from (256 to 470) K. A relative absolute deviation of 2.9 % was observed
when testing the model against 961 data points from 53 different ionic
liquids reported previously and measured within this study.