The volume change on ionizatin of weak electrolytes

1954 ◽  
Vol 7 (4) ◽  
pp. 329 ◽  
Author(s):  
SD Hamann ◽  
SC Lim
Keyword(s):  
Volume Change ◽  
Solvent Effects ◽  
Partial Molar Volumes ◽  
Volume Changes ◽  
Molar Volumes ◽  
Weak Electrolytes

The standard partial molar volumes of some strong and weak electrolytes have been measured in water and three other solvents. The results have been used to estimate the volume changes which accompany the ionization of weak electrolytes. Solvent effects are discussed.

Dilatometric study of streptococcal growth and metabolism

1969 ◽  
Vol 15 (8) ◽  
pp. 933-940 ◽  
Author(s):  
Robert E. Marquis ◽  
Wallace O. Fenn
Keyword(s):  
Lactic Acid ◽  
Volume Change ◽  
Small Volume ◽  
Partial Molar Volumes ◽  
Pressure Sensitivity ◽  
Volume Changes ◽  
Streptococcus Faecalis ◽  
Dilatometric Study ◽  
Cell Synthesis ◽  
Metabolic Volume

A simply constructed dilatometer or volumeter was used to measure small volume changes (ca. 6 × 10−4 ml per milliliter) accompanying growth of Streptococcus faecalis cultures. Polymerization reactions involved in cell synthesis appeared to contribute little to the observed changes, and dilatation of cultures in glucose-containing media could be interpreted mainly in terms of volume changes associated with cleavage of glucose to lactic acid, ionization of lactic acid, and protonation of buffer ions in the culture. Glycolysis in suspensions of nongrowing cells was accompanied by similar increases in volume. In contrast, arginine degradation by S. faecalis was accompanied by contraction, and in this case the volume change could be almost completely accounted for by differences in partial molar volumes of products and reactants. Possible relationships between metabolic volume changes and pressure sensitivity of bacteria are discussed.

Use of Partial Molar Volumes of Model Compounds in the Interpretation of High-Pressure Effects on Proteins

1996 ◽  
Author(s):  
Kenneth E. Prehoda ◽  
John L. Markley
Keyword(s):  
Volume Change ◽  
Atmospheric Pressure ◽  
Protein Unfolding ◽  
Partial Molar Volumes ◽  
Bulk Water ◽  
Pressure Effects ◽  
Molar Volumes ◽  
Positive Term ◽  
Full Characterization ◽  
The Difference

The transfer of liquid hydrocarbons into water is accompanied by a large decrease in volume at 25 °C and atmospheric pressure, with typical values for ΔV°tr of — 2.0 ml mol methylene−1. Considering the large amount of apolar surface that is exposed when a globular protein unfolds, the hydrocarbon transfer results imply that the change in volume accompanying the unfolding process (ΔV°obs) should be highly negative under these conditions. However, experimental data on the pressure denaturation of proteins typically yield relatively small values of ΔV°obs at atmospheric pressure and 25 °C. We analyze this apparent inconsistency in terms of a simple thermodynamic dissection of the partial molar volume. This approach allows the volume effects that result from solute-solvent interactions to be determined from experimental partial molar volumes. The use of absolute quantities (partial molar volumes) circumvents assumptions associated with the use of results from transfer experiments. An important finding is that hydration of apolar species is less dense than bulk water. This discovery leads to the conclusion that the contribution to ΔV°obs for protein unfolding from the hydration of apolar surfaces is highly positive, contrary to predictions based on transfer data. Further, hydration of polar surfaces makes a positive contribution to ΔV°obs. The large, positive term from the differential hydration of the folded and unfolded states is compensated by the difference in free volume of the protein in the two states. This finding provides a new framework for interpreting pressure effects on macromolecules. The full characterization of a macromolecular system requires knowledge of the effect of pressure on the system. The thermodynamic information obtained from using pressure as a perturbation is a volume change for the particular reaction being studied. The observed volume change, ΔV°obs, for protein unfolding may provide insight into the mechanisms that determine the three-dimensional structure of the folded state. Pressure denaturation experiments have been demonstrated for a number of proteins, including ribonuclease A (Gill & Glogovsky, 1965; Brandts et al., 1970), chymotrypsinogen (Hawley, 1971), metmyoglobin (Zipp & Kauzmann, 1973), and, more recently, lysozyme (Samarasinghe et al., 1992) and staphylococcal nuclease (Royer et al., 1993).

Volume changes associated with zeolite ionic exchange

1983 ◽  
Vol 36 (3) ◽  
pp. 419
Author(s):  
GA Bottomley ◽  
JA Evans
Keyword(s):  
Volume Change ◽  
Small Dimension ◽  
Apparent Molar Volumes ◽  
Solution Phase ◽  
Ionic Exchange ◽  
Volume Changes ◽  
Molar Volumes ◽  
Zeolite 13X ◽  
Zeolite 4A ◽  
System Volume

Aqueous suspensions of zeolite(4A) in the potassium and sodium forms have been separately exchanged with Ca2+ at 25�C in a precision dilatometer to measure the associated system volume change, ∆Vobs. Similar experiments partially exchanged K+ into sodium zeolite(4A) and Na+ into potassium zeolite(4A). Tris(ethane-1,2-diamine)cobalt(III) chloride was also exchanged with sodium zeolite(13X). For the overall process ∆Vobs is small, generally well under 10 cm3 per mole of incoming cation exchanged. The results are discussed in terms of three contributions to the overall volume change: (i) the volume change of ionic replacement in the solution external to the zeolite (this is available from the known apparent molar volumes of the electrolytes); (ii) the small dimension changes of the zeolite lattices on exchange; (iii) the transfer of water between zeolite and the solution phase.

Electrostriction volumes of α-amino acids from density measurements in water and in aqueous HCl and NaOH solutions at 25 °C

1993 ◽  
Vol 71 (12) ◽  
pp. 2150-2154 ◽  
Author(s):  
M. Abbate ◽  
G. Castronuovo ◽  
V. Elia ◽  
S. Puzziello
Keyword(s):  
Amino Acids ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Sodium Hydroxide ◽  
Volume Change ◽  
Pure Water ◽  
Partial Molar Volumes ◽  
Molar Volumes ◽  
Density Measurements ◽  
Alkyl Chains

The values of the limiting partial molar volumes, [Formula: see text], for some α-amino acids bearing alkyl chains, in pure water and in aqueous solutions of hydrochloric acid and sodium hydroxide, have been obtained from density measurements. From these data it is possible to determine the volume change, ΔVZW, due to the formation of the amphionic molecule from the corresponding neutral molecule.

The apparent molar volumes of aqueous ammonia, ammonium chloride, aniline and anilinium chloride at 25°C and the volume changes on ionization

1975 ◽  
Vol 28 (10) ◽  
pp. 2109 ◽  
Author(s):  
RH Stokes
Keyword(s):  
Molar Volume ◽  
Ammonium Chloride ◽  
Volume Change ◽  
Apparent Molar Volume ◽  
Infinite Dilution ◽  
Aqueous Ammonia ◽  
Apparent Molar Volumes ◽  
Volume Changes ◽  
Molar Volumes ◽  
Standard States

The apparent molar volumes of aqueous ammonia, ammonium chloride, aniline and anilinium chloride are measured up to 2 mol l-1 at 25�C by a combination of pyknometric and dilatometric methods. The apparent molar volume f�V of undissociated ammonia at infinite dilution is found to be 24.85�0.02 cm3 mol-1, and that of NH4Cl is 35.71�0.02 cm3 mol-1. The volume change on ionization for the standard states ΔV� is -29.07�0.04 cm3 mol-1. For aniline the values are: f�V(PhNH2) 89.30, f�V(PhNH3Cl) 102.74 and ΔV� -26.49�0.05 cm3 mol-1.

Modeling Volume Changes in Proteins Using Partial Molar Volumes of Model Compounds

1996 ◽  
pp. 433-438 ◽  
Author(s):  
Kenneth E. Prehoda ◽  
Stewart N. Loh ◽  
John L. Markley
Keyword(s):  
Partial Molar Volumes ◽  
Volume Changes ◽  
Model Compounds ◽  
Molar Volumes

scholarly journals Thermophysical properties of binary blends of cyclohexane with some esters

2017 ◽  
Vol 82 (2) ◽  
pp. 189-202
Author(s):  
Rajendra Pradhan ◽  
Biswajit Sinha
Keyword(s):  
Methyl Acetate ◽  
Excess Molar Volumes ◽  
Partial Molar Volumes ◽  
Volume Changes ◽  
Pfp Theory ◽  
Excess Isentropic Compressibilities ◽  
Binary Blends ◽  
Molar Volumes ◽  
Derived Properties ◽  
Robinson Equation

From the densities (?) and viscosities (?) measured for three binary blends consisting of methyl acetate (MA), ethyl acetate (EA) and methyl salicylate (MS) over the entire composition range with cyclohexane (CH) at 298.15?318.15 K under atmospheric pressure, the excess molar volumes (VEm ) and excess viscosities (?E) were derived. In addition, the excess isentropic compressibilities (KEs ) excess intermolecular free lengths (LEf) and excess molar refractions (R Em) were derived from measured ultrasonic speeds of sound (u) and refractive indices (nD) for the binary blends at 298.15 K. Various derived properties are discussed in terms of molecular interactions and structural effects. Partial molar volumes ( 0 Vm,1 and 0 Vm,2 ) and excess partial molar volumes ( 0,E Vm,1 and 0,E Vm,2 ) at infinite dilution are also discussed in terms of volume changes in the blends. Furthermore, the excess molar volumes (V Em ) and viscosities (?) of the blends were correlated with the Prigogine?Flory?Paterson (PFP) theory and the Peng?Robinson Equation of State (PR-EOS).

Partial Molar Volumes of Some Multicharged Electrolytes in Aqueous Dimethylformamide at Various Temperatures

1998 ◽  
Vol 63 (4) ◽  
pp. 507-514
Author(s):  
Madan L. Parmar ◽  
Ch. V. Nageshwara Rao ◽  
Suresh Chand Attri
Keyword(s):  
Partial Molar Volumes ◽  
Water Systems ◽  
Molar Volumes ◽  
Density Measurements ◽  
Solution Density ◽  
Aluminium Sulfate ◽  
Ion Interactions

Partial molar volumes of ammonium aluminium sulfate and potassium aluminium sulfate in DMF-water mixtures (5-20 wt.% of DMF) have been determined from solution density measurements at various temperatures and electrolyte concentrations. The data were evaluated by using Masson equation and the obtained parameters were interpreted in terms of ion-solvent and ion-ion interactions. Both electrolytes have been found to act as the structure makers/promotors in DMF-water systems.

Density and Partial Molar Volumes of the Liquid Mixture Water + Methanol + Ethanol + 2-Propanol at 298.15 K and 0.1 MPa

2021 ◽  
Author(s):  
Gabriela Guevara-Carrion ◽  
Robin Fingerhut ◽  
Jadran Vrabec
Keyword(s):  
Liquid Mixture ◽  
Partial Molar Volumes ◽  
Molar Volumes
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