Among the many mixtures measured, only twelve exhibited transitions in the DSC. Table shows the melting points and glass transitions measured for these mixtures. The main complication in applying equation 1 to the mixtures in Table is the absence of literature values of the DH fus for many of the individual components. However, there are literature values for the enthalpy of fusion and melting point of TBACl and lactic acid, which allows the use of equation 1 to calculate activity coefficients for at least one component of most mixtures in Table . Using the mole fractions from Table (supporting information) that includes the water content, the melting point data from Table , and equation 1 shows that only 1:3 ChCl:L-lactic acid (g L-lacticacid = 0.94) and 2:1 TBACl:(S)-acetoxypropionic acid (g TBACl = 1.1) have g ³ 1. The 1:1 TBACl:Lleucic acid and 1:1 TBACl: dimethyl-D-malate only show glass transitions, and the remaining mixtures in Table have g A < 1 (equation 1) at the measured molar ratios indicating that the melting point depression is consistent with the classification as DES. a uncertainty in density is ± 0.001 g/mL, and the uncertainty in viscosity is ± 3-5 mPa-s