Effects of temperature and concentration on interactions in methanol + ethyl acetate and ethanol + methyl acetate or ethyl acetate systems: Insights from apparent molar volume and apparent molar isentropic compressibility study

The density ( d ) and speed of sound ( u ) for the binary systems (methanol + ethyl acetate) and (ethanol + methyl acetate or ethyl acetate) were measured at 298.15, 303.15, 308.15 and 313.15 K and at atmospheric pressure in this work whereas the system (methanol + methyl acetate) was measured in the literature. The apparent molar volume, V φ , isentropic compressibility, k s , and apparent molar isentropic compressibility, k φ , have been calculated using density and speed of sound data, respectively. The limiting apparent molar volume, V φ 0 , and limiting apparent molar isentropic compressibility, k φ 0 , were found by extrapolation to infinite dilution using the Redlich–Mayer equation. The limiting apparent molar volume was used to obtain information about (solute–solvent) and (solute–solute) interactions. The temperature dependence of apparent molar volumes were used to calculate the apparent molar expansibility, E φ 0 , and Hepler's constant, ( ∂ 2 V φ 0 / ∂ T 2 ) P . The isobaric thermal expansion coefficient, α P , was also calculated. Positive k φ 0 values for all binary systems can be attributed to the predominance of solvent intrinsic compressibility over the solute intrinsic effect.