Physical Properties of the Binary Mixtures of Ethanol + Benzene and Ethanol + Pyridine at Five Temperatures under Atmospheric Pressure

Thermodynamic Properties of Ethanol + Pyridine, Ethanol + Benzene, and Pyridine + Benzene Mixtures at Temperature 298.15 K and Under Atmospheric Pressure

“…In contrast, negative values can be seen in binary mixtures where weak dispersion forces are primarily responsible for interaction but may also occur where components are known to interact more strongly [40,41], as in our case of the ethanol + pyridine system. Similar results are observed for binary mixtures of alkanols with pyridine [35,38] and Nmethyl pyrrolidine [42]. The variations of Δn with the volume fraction of the first component in the mixture are shown in Figure 4.…”

“…The negative ΔκS and V E values in the ethanol-rich region indicate that complex formation occurred through π•••HO bonding between the π-electron cloud of the aromatic ring of benzene and the hydroxyl group of ethanol. A further negative contribution may occur from the interstitial accommodation of benzene molecules into the remaining H-bonded ethanol structure [35]. The negative V E and ΔκS values for the ethanol + pyridine system can be attributed mainly to the formation of complexes by strong cross-associated N•••HO interactions.…”

“…When considering V E and ΔκS, then it is known that contributions (i) and (vi) give positive values, while (ii) -(v) contribute negatively to the values of V E and ΔκS [35,38,39]. Having in mind the various contributions operating in the studied systems, then the positive values of ΔκS and V E in the benzene-rich region of the ethanol + benzene system (Figures 1 and 3) can be attributed mainly to the disruption of the H-bonded ethanol structures as the ethanol molecules are added to a large amount of benzene.…”

Densities and Sound Speeds of Ternary Mixtures Methyl tert-Butyl Ether + Toluene + n-Hexane (or Cyclohexane) and Their Binary Subsystems at a Temperature of 298.15 K and under Ambient Pressure

“…The excess molar volumes, V m E , and isentropic compressibility deviations, Δκ S , of the multicomponent mixtures were calculated by using the following equations 37,45…”

“…The excess molar volumes, V m E , and isentropic compressibility deviations, Δκ S , of the multicomponent mixtures were calculated by using the following equations , where κ S = ρ –1 c –2 is the isentropic compressibility of the mixture and C refers to the number of components in the mixture. M i , ρ i , c i , and κ S, i = ρ i –1 c i –2 are the molar mass, density, sound speed, and isentropic compressibility of pure component i , respectively; x i and ϕ i are the mole and volume fractions of component i in the mixture.…”