• Journal of Science Education
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• v.33 no.2
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• pp.317-320
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• 2009

I investigated Korean college students' conception about the volume change of solution when they detected the equivalence point during acid/base titration experiment using method of volume measurement. According to this study, most college students had a misconception that the volume increment was due to the formation of water by neutralization during acid/base titration. However, this is not enough to explain the volume change, neglecting contribution of a salt in solution. I calculated the partial molar volume of NaCl formed to explain the volume increment of solution during HCl/NaOH neutralization. Comparing the result of experiment with the calculation of partial molar volume, I elucidated that the main effect of volume increment was due to the partial molar volume of NaCl formed during HCl/NaOH neutralization. Here I propose to introduce college students to the concept of partial molar volume of the salt formed to reduce misconception about the volume change of solution during acid/base neutralization.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.157-162
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• 2018

The partial molar volumes of an antidepressant in Halobacteriun Halobium and in suspensions of several lipids have been determined at $25^{\circ}C$ it using a excess volume dilatometer. The potency of general antidepressant, Fluoxetine has long been known to correlate with lipid solubility. Denaturations of the vesicle, which is a sole membrane protein in the purple membrane of Halobacteriun Halobium, were studied by absorption changes at 280 nm and fluorescence changes at 330 nm with excess volume dilatometer. The 1H NMR analysis of viscous polymer solutions by diffusion interchange is the important step by measurement. The partial molar volume and particle size of Fluoxetine in Halobacteriun Halobium were measured to be positive. An antidepressant can prevent diseases that produce a variety of cognitive and mental symptoms based on low morale and depression, resulting in poor daily performance.

• Journal of Industrial Technology
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• v.19
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• pp.253-260
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• 1999

Two thermodynamic models were used to predict the partial molar volumes of solutes in supercritical carbon dioxide at infinite dilution: (1) the Peng-Robinson equation of state with various mixing rules including those based on $EOS/G^E$ (2) the Kirkwood Buff fluctuation integral with the hard sphere expansion (HSE) method. The Kirkwood-Buff fluctuation integral method, in which an equation of state for pure component and molecular parameters are required, produced better results especially near the critical point than the Peng-Robinson equation of state with the several mixing rules based an $EOS/G^E$. When the $EOS/G^E$ mixing rules were used, poorer results were obtained compared with the classical mixing rule and Kirkwood-Buff model.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.516-525
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• 2020

The densities of aqueous solutions of the amphiphile 2-(2-hexyloxyethoxy)ethanol (C₆E₂) were measured at 279.15 K and 282.15 K by vibrating-tube densitometry. Then using the density data of the binary C₆E₂ (1)/water(2) system, the excess volumes and partial molar volumes were determined at various compositions. Excess volume V^E exhibits negative deviation for the whole region of composition, which implies relatively stronger attraction between molecules. At the C₆E₂ mole fraction of around 0.45, V^E was at its minimum. Partial molar volume ${\bar{V}}_1$ increases monotonously with the mole fraction x₁(=x) and ${\bar{V}}_2$ decreases with x. Any particular point in ${\bar{V}}_1$ and ${\bar{V}}_2$, which may point to molecular association, was unobserved.

• Bulletin of the Korean Chemical Society
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• v.5 no.3
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• pp.112-117
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• 1984

The association constants (K) of 3,5,N-trimethyl pyridinium iodide in 95 volume percent ethanol-water mixed solvent were determined by a modified UV and conductance method at $25^{\circ},\;30{\circ},\;40{\circ}\;and\;50{\circ}C$ over the pressure range 1 to 2000 bars. The association process is enhanced with increasing pressure and decreasing temperature. From K values, we obtained the total partial molar volume change (${\Delta}V$) and some thermodynamic parameters. The electrostriction volume (${\Delta}V_{el}$) and intrinsic volume (${\Delta}V_{in}$) were also evaluated. The values of ${\Delta}V,\;{\Delta}V_{el},\;{\Delta}V_{in}$ are negative, negative and positive, respectively, and the absolute values of all these three decrease with increasing pressure and temperature. The ion-pair size (a) were varied 3 to 6 ${\AA}$, with pressure and temperature. The solvation number (n) decreased from 2 to 0.5 with increasing temperature.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.85-93
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• 1971

Apparent molal valumes ${\phi}_v$ and relative viscosities ${\eta}_r$ of aqueous solutions of anilinium chloride have been determined at two degree intervals from 20 to $50^{\circ}C$ in the molar concentration range 0.003 < C < 0.4. The results are discussed in terms of partial molal volumes $\={V}^{\circ}$, deviations from the Debye-H$\''{u}$ckel limiting law, partial molal expansibilities $\={E}^{\circ}$, viscosity B coefficients calculated from the Jones-Dole equation, and energy of activation for viscous flow. In aqueous solution, anilinium chloride was found to be a weak structure-maker due to its hydrophobic group.

• Bulletin of the Korean Chemical Society
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• v.2 no.3
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• pp.90-96
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• 1981

The significant structure theory of liquids has been successfully applied to the sodium ammonia solution. In applying the theory to sodium ammonia solution, we assumed there were four species in solution, i.e., sodium cation, solvated electron, triple ion, and free electron and equilibria existed between them. Based on these assumptions, we set up the model explaining the anomalous properties of sodium ammonia solution. The partition function for sodium ammonia solution is composed of the partition functions for the above four species and also for the Debye-Huckel excess free energy term. Agreements between calculated and experimental values of the thermodynamic quantities, such as molar volume, vapor pressure, partial molar enthalpy and entropy, and chemical potential as well as viscosity are quite satisfactory.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.106-112
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• 1994

Six physical properties (molecular weight, heat capacity, side chain weight, side chain volume, standard entropy and partial molar volume) of amino acids, peptides and their derivatives were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index and ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content and polarizability. This paper examines the correlation of the molecular modeling techique's parameters and the physicochemical properties of amino acids and their derivatives. As a result, calculated values were in agreement with experimental data in the above six physical properties of amino acids, peptides and their derivatives and the molecular connectivity index was superior to the other indices in fitting the calculated data.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.266-269
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• 1985

The dissociation constants(K) of m-chloroanilinium ion in water-ethanol mixture, where the volume percentage of water is 89.5%, were evaluated by UV-spectroscopic method at $20{\sim}50^{\circ}C$, up to 1500 bars with changing ionic strength from 0.04 to 0.10 mol $kg^{-1}$ by use of acetate buffer. K values enhance with increasing ionic strength and temperature, but decrease with elevating pressure. From K values, we obtained the partial molar volume change and some other thermodynamic parameters. From the values of enthalpy, entropy and isoequilibrium temperature (649 K), we concluded that the dissociation of m-chloroanilinium ion mentioned above is controlled by enthalpy.

• Coupled systems mechanics
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• v.8 no.2
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• pp.129-146
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• 2019

The main goal of this work is to develop a numerical simulator to study an isothermal single-phase two-component flow in a naturally fractured oil reservoir, taking into account advection and diffusion effects. We use the Peng-Robinson equation of state with a volume translation to evaluate the properties of the components, and the discretization of the governing partial differential equations is carried out using the Finite Difference Method, along with implicit and first-order upwind schemes. This process leads to a coupled non-linear algebraic system for the unknowns pressure and molar fractions. After a linearization and the use of an operator splitting, the Conjugate Gradient and Bi-conjugated Gradient Stabilized methods are then used to solve two algebraic subsystems, one for the pressure and another for the molar fraction. We studied the effects of fractures in both the flow field and mass transport, as well as in computing time, and the results show that the fractures affect, as expected, the flow creating a thin preferential path for the mass transport.