On the Evaluation of the Second Virial Coefficient and Activity in Dilute Solution by Vapor Pressure Osmometry

Kamide, Kenji

doi:10.1295/koron1944.25.648

Cited by 5 publications

(5 citation statements)

References 7 publications

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“…Despite the limited info on suitable concentration ranges, VPO has seen use at up to nearly 10% mole percent, giving solute mass fractions of over 50% . Neither the current evaluation nor earlier literature evaluations extend to those relatively high concentrations. ,,, …”

Section: Resultsmentioning

confidence: 75%

“…11,16 Despite the reported issues, VPO can yield accurate chemical activity values and osmotic coefficients. 2,3,9,17,18 In particular, the work of Widera et al demonstrates that VPO can be more precise than direct vapor pressure measurements. One major difference from a hanging-drop type VPO is that the UIC Jupiter 833 19 uses standing thermistors with a mesh cap placed on each.…”

mentioning

confidence: 99%

“…The accuracy of a vapor pressure osmometer can be impacted by a number of conditions including sample dilution, drop size effects, thermistor self-heating, bridge voltage dependency, and solute build up in the reservoir. − The severity of these effects is dependent on the instrument design, ,,, and careful design of the measurement cell and electronics ,, can promote accurate molecular weight determination. , Despite the reported issues, VPO can yield accurate chemical activity values and osmotic coefficients. ,,,, In particular, the work of Widera et al demonstrates that VPO can be more precise than direct vapor pressure measurements.…”

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confidence: 99%

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Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Gray

Nilsson

2018

Anal. Chem.

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Vapor pressure osmometry presents a convenient method to measure chemical activity. The work presented here was carried out to provide confidence in using this technique for a VPO model that does not utilize the "hanging-drop" method. While validation studies are available for certain models of vapor pressure osmometers, none were located for the UIC Jupiter 833 osmometer. This study addresses that need by providing a comparison between original experimental data on sodium chloride, calcium chloride, and sodium sulfate solutions to values calculated using the Pitzer equations. A comparison is also made for experimental data on sucrose with a literature correlation. This study briefly reviews the assumptions going into the equation used to relate the osmometer signal to the diluent activity in order to identify potential sources of the error and the noise in the data. The experimental data shows that the UIC 833 osmometer yields diluent activity values accurate to an average of 0.02%, allowing calculation of osmotic coefficients and solute activity coefficients. Further studies need to be conducted on the accuracy at concentrations above 1.4 m. Qualitatively, however, comparison suggests the UIC Jupiter 833 osmometer yields more scatter in the experimental data than the Knauer instruments. Using more uniform mesh caps on the thermistors could possibly reduce that scatter. Finally, we show that replacing the glass thermistors with in-house made thermistors with Teflon incorporated in the structure give reproducible results and that certain modifications to the design are possible without losing accuracy in the measurements.

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Section: Resultsmentioning

confidence: 75%

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confidence: 99%

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confidence: 99%

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Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Gray

Nilsson

2018

Anal. Chem.

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“…This method, developed originally for the estimation of molecular mass, has been well-established. − The currently used thermistor-type vapor pressure commercial osmometers give the solvent activities rapidly, but they are usually less accurate than the alternative vapor-pressure methods . Nevertheless, vapor pressure osmometry is a suitable technique for measuring the solvent activity at a low molality.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The isopiestic chamber (4) is propped from beneath at its center by a stainless steel needle (19) fixed on the perforated bottom plate (3) (see also Figure S10, Supporting Information). A low-speed gear motor ( 13) is connected to a rotating mechanism (16), which transmits rotation to the isopiestic chamber via a plastic fork (18). As a result, the isopiestic chamber makes movement that could be described as rotation around the inclined axis (precession).…”

Section: ■ Introductionmentioning

confidence: 99%

Measurement of the Osmotic Coefficients in Aqueous Solutions of Imidazolium Ionic Liquids ([C_nmim]Cl or [C_nmim]Br, n = 4, 6, 8) Over a Wide Salinity Range at 298.15 K

Korchak,

Safonova,

Victorov

2023

J. Chem. Eng. Data

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The goal of this work is to provide accurate and detailed experimental data on the osmotic coefficients and the activity of water for the binary aqueous solutions of ionic liquids [C n mim]Cl and [C n mim]Br (n = 4, 6, and 8), covering the broad range of salinity up to 10 mol•kg −1 . Such data form the basis for the thermodynamic description of the system, and are needed, in particular, for the estimation of parameters of thermodynamic models. Our data supplement and extend to a broader concentration range the existing literature data on the studied systems at 298.15 K. The systematic presentation of the data includes the method used, the conditions, the concentration range, and the estimates of the experimental errors. To help in the assessment of the data quality, we compare all of the available data sets. Using vapor pressure osmometry and isopiestic methods to perform experiments, we discuss possible sources of error and explain in every detail the construction of the apparatus designed in our lab to reduce the experimental errors to a minimum. For [C 8 mim]Cl and [C 8 mim]Br, known to form micelles in aqueous solutions, we estimate the critical micelle concentration from our experimental data on the osmotic coefficients and the activity of water.

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Theory of vapor pressure osmometry when ambient solvent vapor is unsaturated

1970

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The general theory of the vapor pressure osmometry has been established, as an extension of the KAMIDE and SANADA theory, in the case when ambient vapor phase is unsaturated. The temperature difference (T, Tv)8 a t the steady state between a solution drop and a solvent drop can be expressed in a form of virial expansion of concentration c in the form :[ Mc l with Ks = Ki/Ki R T~, V~ Ke T aH T n and Tv are the temperatures of the solution and solvent drops, respectively, M1 the molecular weight of the solute, A Z ,~ the second virial coefficient, R the gas constant, T, the temperature of ambient vapor phase, 4 H the molar heat of condensation of the solvent, k: and kn the coefficients of heat transfer at the interfaces between vapor and the solution drop and between the solution and the thermistor, respectively, An the surface area of the solution drop, An the surface area of the thermistor in contact dith the solution, Po(Ts)saturated vapor &essure of the solvent at the temperature Ts, k ' the saturation coefficient defined by the ratio of the real unsaturated pressure of ambient vapor phase to the saturated pressure a t the same temperature, and VO the molar volume of the solvent.

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On the Evaluation of the Second Virial Coefficient and Activity in Dilute Solution by Vapor Pressure Osmometry

Cited by 5 publications

References 7 publications

Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Measurement of the Osmotic Coefficients in Aqueous Solutions of Imidazolium Ionic Liquids ([C_nmim]Cl or [C_nmim]Br, n = 4, 6, 8) Over a Wide Salinity Range at 298.15 K

Theory of vapor pressure osmometry when ambient solvent vapor is unsaturated

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On the Evaluation of the Second Virial Coefficient and Activity in Dilute Solution by Vapor Pressure Osmometry

Cited by 5 publications

References 7 publications

Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Accuracy, Repeatability, and Limitations for Determination of Chemical Activities from Vapor Pressure Osmometry

Measurement of the Osmotic Coefficients in Aqueous Solutions of Imidazolium Ionic Liquids ([Cnmim]Cl or [Cnmim]Br, n = 4, 6, 8) Over a Wide Salinity Range at 298.15 K

Theory of vapor pressure osmometry when ambient solvent vapor is unsaturated

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Product

Resources

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Measurement of the Osmotic Coefficients in Aqueous Solutions of Imidazolium Ionic Liquids ([C_nmim]Cl or [C_nmim]Br, n = 4, 6, 8) Over a Wide Salinity Range at 298.15 K