“…In the present study, limiting activity coefficients of ethanol, propan-1-ol, butan-1-ol, cyclohexane, benzene and toluene in [HPy][NTf 2 ] were also measured by the dilutor technique at four different temperatures in the range of (303.15 to 343.15) K. For accurate estimation of the vapour phase volume required in equation (1), the density of the ionic liquid was measured within the temperature range from (293.15 to 353.15) K. The newly obtained results are compared to previously published [21][22][23] values in table 6 and plotted in figure 7. From figure 7, good agreement is observed between the experimental and literature values reported [22,23] except [21], which show a maximum deviation of ±0.00964 g Á cm À3 .…”