Our previous results xA and xA indicated that the

Table 2.
Densities, ρ, speeds ITF2357 sound, u, viscosities, η and refractive indices , nD data for acetonitrile and ionic liquid at different temperatures.T (K)10− 3ρ (kg·m− 3)u (m·s− 1)η (m Pa·s)nDExp.Lit.Exp.Lit.Exp.Lit.Exp.Lit.Acetonitrile288.150.7873950.78726 [27]1319.070.3881.34610.787376 [28]298.150.7766150.77664 [29]1211 1278.591278.59 [31]0.3440.342 [32]1.34121.34163 [34]0.77666 [30][30]0.341[33]1.3411 [33]0.3369[30]1.3414 [35]308.150.7658100.76586 [34]1238.341238.21[31]0.3130.314 [33]1.33711.3365 [37]0.75942 [36]0.317 [33]0.76589 [27]318.150.7548510.75498 [38]1198.251198.15 [31]0.2890.292 [39]1.33271.3327 [37]0.2974 [40][HMIm]Br298.151.22211.2235 [41]Full-size tableTable optionsView in workspaceDownload as CSV
2.2. Synthesis of ionic liquid
2.3. Apparatus and procedure
The viscosities were measured using an Ubbelohde-type viscometer, which has a flow time of about 200 s for water at 298.15 K. The viscometer was calibrated with doubly distilled deionized water. Viscosity of solutions η is obtained by the following Eq.  (1):equation(1)ηρ=Lt−Ktwhere ρ is the density, t is the flow time of the solution, L and K are the viscometer constants [51]. A digital stopwatch with a resolution of 0.01 s has been used for the measurement of flow time. The evaluated uncertainty of the experimental viscosity was ± 0.005 mPa·s.