scholarly journals Cibulka correlation for ternary excess molar volumes for [MOA]⁺[Tf₂N]⁻ at different temperatures

2012 ◽  
Author(s):  
◽  
Zikhona Tywabi

In this work, the binary and ternary excess molar volumes have been calculated from the density, ρ, measurements using an Anton Paar (DMA 38) vibrating tube digital densimeter. One component of the ternary systems studied was an ionic liquid. The ionic liquid used is methyl trioctylammonium bis(trifluoromethylsulfonyl)imide [MOA]+[Tf2N]-. Binary excess molar volumes were obtained for (1-butanol + ethyl acetate) and (2-butanol + ethyl acetate) systems at T = (298.15, 303.15, and 313.15) K. Ternary excess molar volumes were obtained for the mixtures {[MOA]+[Tf2N]- + 2-propanol or 1-butanol or 2-butanol + ethyl acetate} at T = (298.15, 303.15, and 313.15) K. The Redlich-Kister equation was fitted to the calculated binary excess molar volume data to obtain the fitting parameters which were used to calculate the partial molar volumes at infinite dilution. The calculated partial molar volume was used to better understand the intermolecular interactions of each component at infinite dilution. The Redlich-Kister parameters were also used in the Cibulka equation and the Cibulka equation was used to correlate the ternary excess molar volume data to give the fitting parameters. The binary excess molar volumes,VmE , for the (1-butanol + ethyl acetate) and (2-butanol + ethyl acetate) are positive at each temperature over the entire composition range. At high mole fractions of the alcohol for the binary systems (2-propanol or 1-butanol or 2-butanol + ethyl acetate), VmE is positive again, similar to the Cibulka ternary correlation. The positive V E m values are due to the breaking of intermolecular interactions in the pure components during the mixing process. The ternary excess molar volume,V E 123 , values are negative for all mole fractions. The negative values are due to a more efficient packing and/ or attractive intermolecular interactions in the mixtures than in the pure liquid. There is also a contraction in volume which can be attributed to electron-donor-acceptor type interactions between the ionic liquid and 2-propanol or 1-butanol or 2-butanol as well as ethyl acetate.

2016 ◽  
Author(s):  
◽  
Mbalenhle B. Nduli

The thermophysical properties of the binary mixtures containing biofuel components derived from biomass were determined. Experimental densities, speed of sound, and refractive indices for the binary mixtures (methanol or 1-ethyl-3-methylimidazolium acetate [EMIM][OAc] + furfural or furfuryl alcohol ) were measured at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. From the experimental data, excess molar volume, E m V , isentropic compressibility, s  , molar refractions, R, and deviation in refractive index, Δn, were calculated. The excess molar volumes were found to be negative for all systems studied. The isentropic compressibility were found to be both positive for the whole composition and temperature range and increases slightly with increasing temperature. The deviation in refractive index was positive over the whole composition range. The obtained values of excess molar volumes and changes of refractive index on mixing were satisfactorily correlated by the Redlich–Kister equation. The Lorentz–Lorenz equation was applied to predict the density and calculate the excess molar volume of the binary mixtures.


2015 ◽  
Vol 2 (2) ◽  
pp. 133-148
Author(s):  
Md. Zaved Hossain Khan ◽  
Md Helal Uddin ◽  
Md Shahrul Islam ◽  
G.M Arifuzzaman Khan ◽  
Md. Abdullah Al Muhit ◽  
...  

Densities, p, and viscosities, ?, of four binary systems: N,N-dimethyl formamide (DMF) + 1-propanol, DMF + 2-propanol, DMF + butanol and DMF + 1-pentanol have been measured at five different temperatures ranging form 303.15K to 323.15K at an interval of 5K. Excess molar volumes were found to be negative over the entire concentration ranges. The negative excess molar volume decreases with the increase of chain length of alcohol, the magnitude follows the order DMF+ 1-propanol >, + 2-propanol >, +butanol >, + 1-pentanol. The change of viscosity has been found to be sensitive to the chain length of alcohols. Excess viscosities and Grunberg- Nissan interaction parameters have been found to be positive for DMF + 1-propanol and DMF + 2-propanol systems, and negative for other two systems DMF + butanol and DMF + 1-pentanol. The thermodynamic energy of activation; such as, positive ?G#E each also compatible with the observation.


1993 ◽  
Vol 46 (2) ◽  
pp. 243 ◽  
Author(s):  
F Corradini ◽  
G Franchini ◽  
L Marcheselli ◽  
L Tassi ◽  
G Tosi

Densities (p) are presented for aqueous binary mixtures of ethane-1,2-diol at different mole fractions covering the whole miscibility field and at various temperatures (t) in the -10 ≤ t/°C ≤ +80 range. The values of the excess molar volume ( VE ) are discussed in terms of: ( i ) the influence of interactions between the components; (ii) order and degree of packing in the pure species and in the mixtures; (iii) free volume differences.


2018 ◽  
Author(s):  
◽  
Ncomeka Mgxadeni

In this study the experimental density, speed of sound, and refractive index for binary mixtures of an ionic liquid (IL): 1-butyl-3-methylimidazolium nitrate and activity coefficients at infinite dilution of organic solutes in the ionic liquid: 1-butyl-3-methylimidazolium hydrogen sulfate were determined. The density, speed of sound, and refractive index of 1-butyl-3-methylimidazolium nitrate in pyridine or acetonitrile or thiophene have been reported at T = 298.15 K, 303.15 K, 308.15 K, 313.15 K and 318.15 K using an Anton Paar DSA 5000M vibrating U-tube densimeter and a RXA 156 refractometer. The derived properties namely: excess molar volume, isentropic compressibility and change in refractive index were calculated from density, speed of sound and refractive index, respectively. The results are discussed in terms of molecular interactions (hydrogen bond, dipole-dipole, or ion-solvent or interactions). The negative deviation of excess molar volume and the positive deviation in change in refractive index clearly indicates the strong interaction of 1-butyl-3-methylimidazolium nitrate with pyridine or acetonitrile or thiophene in solution. The positive values of isentropic compressibility for the system indicates that the mixtures were more compressible than the ideal mixture. The Redlich Kister smoothing polynomial was used to fit the excess molar volume and deviation in isentropic compressibility data. The Lorentz-Lorenz equation was used to predict the experimental density, or refractive index data and to correlate the excess molar volume. Gas liquid chromatography was used to determine activity coefficients at infinite dilution for 28 polar and non-polar organic solute: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, aldehydes, thiophene, pyridine and acetonitrile in an IL: 1-butyl-3- methylimidazolium hydrogen sulfate ([BMIM][HSO4]). The measured values of activity coefficients at infinite dilution for the solutes in [BMIM][HSO4] were carried out at T = (313.15, 323.15, 333.15) K. Partial molar excess enthalpies at infinite dilution of the organic solutes in the ionic liquid have been calculated from the temperature dependence of activity coefficients at infinite dilution. The selectivity and capacity values for separation problems namely: hexane/benzene, heptane/benzene, cyclohexane/benzene, ethanol/benzene, heptane/pyridine, heptane/thiophene and methanol/acetone at T = 323.15 K were calculated and compared to literature values for similar ionic liquids, sulfolane and N-methyl-2- pyrolidinone (NMP). The IL [BMIM][HSO4] gave both the highest selectivity and limiting capacity for the heptane/thiophene separation and would therefore be a suitable entrainer for this separation. New data from this study reveals that [BMIM][HSO4] may be proposed as a replacement solvent for the separation of sulphur or nitrogen compounds from alkanes.


2021 ◽  
Vol 18 (2) ◽  
pp. 171-178
Author(s):  
Sampandam Elangovan

A binary liquid mixture that consists of ethyl acetate and 1-ethanol has been prepared at various concentrations by the mole fraction method. The ultrasonic velocity and density have been determined at 303K, 308K and 313K. From the experimental data, the excess isentropic compressibility, excess molar volumes, excess internal pressures, and excess molar enthalpy have been computed. The variations were observed as polynomial and fitted to the Redlich-Kister polynomial functions. By using this function, adjustable parameters and the standard deviations have been calculated. The experimental and theoretical data reveal that the existence of the intermolecular interactions between the selected liquid system. The partial molar compressibility’s and partial molar volume also calculated at infinite dilution of the system. In general, the intermolecular forces have tended to the variations in the magnitude and sign of the excess parameters. The excess molar volume (Vme), excess isentropic compressibility (), excess internal pressure ( ) and the enthalpy ( ) show the negative magnitude at the entire range of concentrations and temperatures. The significant variations of these parameters with the mole fraction of ethyl acetate have been analysed. Furthermore, the strength of the intermolecular interactions decreased with increasing the experimental temperatures as 303K > 308K >313K.


2004 ◽  
Vol 1 (2) ◽  
pp. 274-279
Author(s):  
Baghdad Science Journal

Excess molar volumes of five ternary mixtures of 2- methoxy ethanol(1) +butyl acetate(2)+benzene(3), +toluene(3), +chlorobenzene(3), +bromobenzene(3), and +nitrobenzene(3) have been measured at 303.15K. The excess molar volume exhibited positive deviation over the entire range of composition in the systems 2-methoxy ethanol(1)+ butyl acetate(2)+ benzene(3),+toluene(3) and sigmoid behavior in the case of the remaining systems. Flory's statistical theory have been extended to predict the excess molar volumes of the five ternary mixtures at 303.15 k over a wide range of composition . An excellent agreement has been found between the experimental and theoretical excess molar volumes , both in magnitude and sign .


2009 ◽  
Author(s):  
◽  
Precious N. Sibiya

The thermodynamic properties of binary liquid mixtures involving ionic liquids (ILs) with alcohols were determined. ILs are an important class of solvents since they are being investigated as environmentally benign solvents, because of their negligible vapour pressure, and as potential replacement solvents for volatile organic compounds (VOCs) currently used in industries. Alcohols were chosen for this study because they have hydrogen bonding and their interaction with ILs will help in understanding the intermolecular interactions. Also, their thermodynamic properties are used for the development of specific chemical processes. The excess molar volumes of binary mixtures of {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from experimental density values, at T = (298.15, 303.15 and 313.15) K. The Redlich-Kister smoothing polynomial was fitted to the excess molar volume data. The partial molar volumes of the binary mixtures {1-ethyl-3-methylimidazolium ethylsulfate + methanol or 1-propanol or 2-propanol}, {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, {1-buty-3-methylimidazolium methylsulfate + methanol or ethanol or 1-propanol} were calculated from the Redlich-Kister coefficients, at T = (298.15, 303.15 and 313.15) K. This information was used to better understand the intermolecular interactions with each solvent at infinite dilution. iii The isentropic compressibility of {trioctylmethylammonium bis (trifluoromethyl-sulfonyl) imide + methanol or ethanol or 1-propanol}, were calculated from the speed of sound data at T = 298.15 K.


1983 ◽  
Vol 48 (8) ◽  
pp. 2327-2334
Author(s):  
Otakar Söhnel ◽  
Petr Novotný ◽  
Zdeněk Šolc

Two methods are given for assessment of density of binary aqueous solutions of electrolytes; one is based on partial molar volume of the dissolved electrolyte at infinite dilution, and the other is based on additivity of apparent molar volumes at a given concentration. The density estimates of aqueous solutions by means of the two methods are compared with experimental values for some electrolytes of the type 1-1 to 4 and 2-2. In all cases the estimates agree with experimental densities up to concentrations of the saturated solutions.


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