Separation of limiting equivalent conductances into ionic contributions in non-aqueous solutions by indirect methods

1983 ◽  
Vol 79 (3) ◽  
pp. 571 ◽  
Author(s):  
Boris S. Krumgalz
Keyword(s):  
Aqueous Solutions ◽  
Indirect Methods ◽  
Limiting Equivalent Conductances

CONDUCTANCES OF AQUEOUS SOLUTIONS OF SODIUM OCTANOATE AT 25° AND 35° AND THE LIMITING CONDUCTANCE OF THE OCTANOATE ION

1962 ◽  
Vol 40 (5) ◽  
pp. 839-844 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
G. R. Lakshminarayanan
Keyword(s):  
Aqueous Solutions ◽  
Micelle Formation ◽  
Sodium Octanoate ◽  
Limiting Equivalent Conductances

Equivalent conductances, densities, and viscosities of aqueous solutions of sodium octanoate have been determined at 25° and 35 °C, at concentrations ranging from 0.0002 M to 2.8 M. The limiting equivalent conductances of the octanoate ion have been determined as 23.08 mhos and 29.09 mhos, at 25° and 35 °C respectively.Comparison has been made of our experimental conductances with those calculated, using the equations of Robinson–Stokes, of Falkenhagen–Leist, and of Fuoss.No evidence has been found of micelle formation in solutions of sodium octanoate.

THE LIMITING EQUIVALENT CONDUCTANCES OF AMMONIUM CHLORIDE, AMMONIUM BROMIDE, AND AMMONIUM NITRATE AT 35.00 °C.

1958 ◽  
Vol 36 (2) ◽  
pp. 330-338 ◽  
Author(s):  
A. N. Campbell ◽  
E. Bock
Keyword(s):  
Aqueous Solutions ◽  
Ammonium Nitrate ◽  
Ammonium Chloride ◽  
Stokes Equation ◽  
Probable Error ◽  
Ammonium Bromide ◽  
Conductance Data ◽  
Ionic Conductances ◽  
Hydrolysis Of ◽  
Limiting Equivalent Conductances

The limiting equivalent conductances of ammonium chloride, ammonium bromide, and ammonium nitrate as well as the limiting ionic conductances of the ammonium and nitrate ions were determined at 35 °C. with a probable error of 0.05%. The values found were [Formula: see text] 180.97 mhos, [Formula: see text] 182.73 mhos, [Formula: see text] 174.21 mhos, [Formula: see text] 88.73 mhos, and [Formula: see text] 85.48 mhos. These values were obtained by the application of the Shedlovsky method of extrapolation to equivalent conductance data, which had been corrected for the hydrolysis of the ammonium ion.Observed equivalent conductances of aqueous solutions of ammonium nitrate at 35 °C., in the concentration range from 0.0002 N to 10 N, have been compared with those calculated by means of the Wishaw–Stokes and Falkenhagen–Leist equations. The Wishaw–Stokes equation was found to give better agreement with experiment than the Falkenhagen–Leist equation.

CONDUCTANCES OF AQUEOUS SOLUTIONS OF SODIUM HEXANOATE (SODIUM CAPROATE) AND THE LIMITING CONDUCTANCES OF THE HEXANOATE ION, AT 25 °C AND 35 °C

1960 ◽  
Vol 38 (10) ◽  
pp. 1939-1945 ◽  
Author(s):  
A. N. Campbell ◽  
J.I. Friesen
Keyword(s):  
Molecular Weight ◽  
Aqueous Solutions ◽  
Stokes Equation ◽  
Apparent Molecular Weight ◽  
Ionic Micelles ◽  
Limiting Conductances ◽  
Limiting Equivalent Conductances

The equivalent conductances, densities, and viscosities of aqueous solutions of sodium hexanoate have been determined at 25 °C and 35 °C at concentrations ranging from 0.0003 M to saturation.The limiting equivalent conductances of the hexanoate ion have been determined as 27.37 ± 0.04 mhos at 25 °C and 34.69 ± 0.05 mhos at 35 °C.The Robinson–Stokes and the Falkenhagen–Leist equations have been applied to the data. The Robinson–Stokes equation reproduces the data within 0.7 mho up to 0.5 M at 25 °C when å = 13 Å. At 35 °C the data are reproduced within 0.5 mho up to 0.05 M with å = 10 Å. The Falkenhagen–Leist equation reproduces the data at 25 °C within 0.4 mho up to 0.1 M with å = 5.5 Å. An å = 4.0 Å reproduces the 35 °C data within 0.5 mho up to 0.05 M.From the form of the conductance curves and from an estimation of the apparent molecular weight it was concluded that the hexanoate ion does not form ionic micelles.

CONDUCTANCES AND SURFACE TENSIONS OF AQUEOUS SOLUTIONS OF SODIUM DECANOATE, SODIUM LAURATE, AND SODIUM MYRISTATE, AT 25° AND 35°

1965 ◽  
Vol 43 (6) ◽  
pp. 1729-1737 ◽  
Author(s):  
A. N. Campbell ◽  
G. R. Lakshminarayanan
Keyword(s):  
Aqueous Solutions ◽  
Micelle Formation ◽  
Sodium Formate ◽  
Sodium Laurate ◽  
Surface Tensions ◽  
Sodium Propionate ◽  
Reversible Dimerization ◽  
Experimental Values ◽  
Sodium Decanoate ◽  
Limiting Equivalent Conductances

The equivalent conductances of aqueous solutions of sodium decanoate, sodium laurate, and sodium myristate have been determined from the very dilute region up to saturation concentration, at 25° and 35°. The limiting conductances have been obtained from the measurements in the usual way. In addition and for the sake of completeness, the limiting equivalent conductances of sodium formate, sodium acetate, sodium propionate, and sodium butyrate have also been determined at 35°, since they were not known at this temperature.The effect of increasing chain length on mobility is discussed. From a consideration of the experimental and the theoretical values of the slopes of the plots of equivalent conductance against the square root of the concentration, it is concluded that some sort of interaction, possibly a reversible dimerization of anions, occurs, even in the dilute region, and this could account for the lower experimental values of the slope. This phenomenon has been observed with other long chain electrolytes, however, and the hypothesis of dimerization is not the only possible one.The critical micelle concentrations have been determined, and recent concepts of micelle formation are applied to interpret their structure. The surface tensions of the aqueous solutions have been measured at 25° and 50°.

THE LIMITING CONDUCTANCE OF AQUEOUS SOLUTIONS OF POTASSIUM IODATE, POTASSIUM CHLORATE, AND SILVER NITRATE AT 35.00 °C

1959 ◽  
Vol 37 (5) ◽  
pp. 889-892 ◽  
Author(s):  
E. Bock ◽  
A. N. Campbell
Keyword(s):  
Aqueous Solutions ◽  
Silver Nitrate ◽  
Association Constants ◽  
Potassium Chlorate ◽  
Potassium Iodate ◽  
Extrapolation Procedure ◽  
Limiting Equivalent Conductances

Measurements have been made of the equivalent conductances of aqueous solutions of potassium iodate, potassium chlorate, and silver nitrate at 35.00 °C at concentrations ranging from 0.8 × 10−4 to 16×10−4 N. From these, the limiting equivalent conductances and association constants A as obtained by the use of the Fuoss–Shedlovsky extrapolation procedure were found to be at 35.0 °C:[Formula: see text]

THE ELECTROLYTIC CONDUCTANCES OF SODIUM CHLORATE AND OF LITHIUM CHLORATE IN WATER AND IN WATER–DIOXANE

1966 ◽  
Vol 44 (8) ◽  
pp. 925-934 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
B. G. Oliver
Keyword(s):  
Aqueous Solutions ◽  
Stokes Equations ◽  
Sodium Chlorate ◽  
Limiting Equivalent Conductances ◽  
Onsager Equation

The conductances, densities, and viscosities of aqueous solutions of sodium chlorate were determined over the complete range of concentration at 25 °C and at 35 °C. An attempt was made to reproduce the results at 25 °C with the viscosity-corrected Falkenhagen–Leist and Wishaw–Stokes equations. The limiting equivalent conductances of sodium chlorate at 25 °C and 35 °C in water were also determined.The conductances, densities, and viscosities of sodium chlorate at 25 °C and 35 °C were determined in a solvent consisting of 64.5% dioxane, 35.5% water. The limiting equivalent conductances of sodium chlorate at 25 °C and 35 °C and of lithium chlorate at 25 °C in this solvent were determined by analyzing the data with the Fuoss–Onsager equation for associated electrolytes.Finally, conductances of sodium chlorate and lithium chlorate at 25 °C were determined in a solvent consisting of 90% dioxane, 10% water.

Conductances of electrolytes in solutions of the sucrose polymer Ficoll

1964 ◽  
Vol 17 (3) ◽  
pp. 304 ◽  
Author(s):  
RH Stokes ◽  
IA Weeks
Keyword(s):  
Aqueous Solutions ◽  
Polymer Molecules ◽  
Sucrose Solutions ◽  
Limiting Conductances ◽  
Limiting Equivalent Conductances

The limiting equivalent conductances of several electrolytes have been measured at 25� in aqueous solutions of the synthetic sucrose polymer Ficoll. Though the viscosity of the solutions is several times that of sucrose solutions of the same percentage by weight of solute, the limiting conductances of small ions in them are little different from those in sucrose solutions. It is concluded that the polymer molecules form loose networks to a large extent permeable to small ions.

Ultrathin frozen sections of yeast without aldehyde prefixation

1978 ◽  
Vol 36 (2) ◽  
pp. 58-59
Author(s):  
K. J. Böhm ◽  
a. E. Unger
Keyword(s):  
Aqueous Solutions ◽  
Biological Material ◽  
Yeast Cells ◽  
Frozen Sections ◽  
Good Preservation ◽  
Ultrathin Frozen Sections

During the last years it was shown that also by means of cryo-ultra-microtomy a good preservation of substructural details of biological material was possible. However the specimen generally was prefixed in these cases with aldehydes.Preparing ultrathin frozen sections of chemically non-prefixed material commonly was linked up to considerable technical and manual expense and the results were not always satisfying. Furthermore, it seems to be impossible to carry out cytochemical investigations by means of treating sections of unfixed biological material with aqueous solutions.We therefore tried to overcome these difficulties by preparing yeast cells (S. cerevisiae) in the following manner:

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

Sign in / Sign up

Export Citation Format

Share Document