A Measurement of the Magnitude of the Electrokinetic Current in Liquid Flow through a Single Capillary

The potential difference, E, between the two ends of a capillary, through which a steady flow of liquid was maintained, was measured by means of unpolarizable electrodes connected to a potentiometer circuit, and at the same time shunted through a known resistance, R. The value of R was varied from 1 to 98000 megohms. For each value of R there was a corresponding value of E, and a current, I (=E/R), through the resistance. The electrokinetic current, Ie, was obtained by extrapolating the plot of E/R versus R to the limit R=O

Vapor Density, Liquid Density and Surface Tension of Solutions of Potassium Thiocyanate in Liquid Sulfur Dioxide for 10° to 25° C

The vapor density, liquid density and differential capillary rise of pure liquid sulfur dioxide, and sulfur dioxide solutions of potassium thiocyanate were measured at 10, 15, 20, and 25°C in a sealed apparatus which allowed the measurement of all these quantities on the same solution. The apparatus consisted of two Pyrex capillaries sealed on to a Pyrex tube of 16.3 mm diameter in which a quartz bob was suspended from a calibrated quartz spring. By weighing the bob in the vapor, inverting, and weighing in the liquid, the densities could be determined to ± 0.02 mg/ml. All distances including the capillary heights were measured by a special microscope which could be read to ±0.00006 cm. Differential capillary rises could be duplicated to better than ± 0.0002 cm. From the surface tension and its rate of change with temperature the Fötvös constant, critical temperature, total surface energy and Paracor for sulfur dioxide were calculated. For the concentrations of potassium thiocyanate studied, a rise in the surface tension and liquid density was found at each temperature

The Formation of Gas Bubbles in Liquids

Gas bubbles which were formed by passing nitrogen through a glass capillary into liquids were studied by means of stroboscopic frequency measurements, rate of gas flow, and instantaneous ( approx. 10-5 sec. exposure) photographs. The size of the bubbles was determined both from the frequency and rate of gas flow and from measurements of the photographic images of the bubbles. The following pure liquids and solutions were used at room temperature: ethyl alcohol, n-propyl alcohol, aniline, acetone, benzene, chloroform, carbon tetrachloride, methyl alcohol, n-butyl alcohol, ether, and three aqueous solutions of ethyl alcohol. The pressures used were varied from the lowest pressure which would give a steady stream of bubbles (approx. 0.6 cm. of Hg) up to about 2.3 cm. of Hg. Capillary diameters were from 0.0137 to 0.0341 cm. The bubble frequency was practically constant (45-50 bubbles/sec.) for the pure liquids studied at all pressures and capillary diameters used. It follows therefore that the size of each bubble (cm3) is directly proportional to the rate of gas flow (cm3/sec.) and is independent of the properties of the liquid and the capillary diameter in the range of experimental conditions used. Higher pressures, larger capillary diameters, and lower surface tension give larger bubbles as a result of the increased rate of flow. In the case of 20.2, 70.0, and 40.7 per cent aqueous solutions of ethyl alcohol the bubble frequency was greater than with pure liquids and showed a much greater variation with pressure

Vapor-Pressure Lowering of Sulfur Dioxide Solutions of Potassium Thiocyanate from 15 to 25 C. (Abstract)

The vapor-pressure lowering of sulfur dioxide by potassium thiocyanate at 15°, 20° and 25° C. was measured by means of a differential mercury manometer connected to an all glass apparatus which employed no stopcocks. Readings were made to 0.001 cm. with a cathetometer. All concentrations were corrected for the amount of sulfur dioxide in the vapor phase. The molal lowering was approximately one-half the theoretical value at 0.005 molal and decreased with increasing concentration up to 1 molal, the highest concentration studied

The Transference Numbers and the Degree of Solvation of the Ions of Lithium Chloride in Certain Alcohols

The low migration velocities of some of the ions of the elements of low atomic weight, as well as the many other phenomena that are not explained by simple electrolytic dissociation, have led to the belief that the ion does not lead an independent existence in the solution, but is solvated, or combined chemically with one or more molecules of the solvent

Electrokinetic Potentials at Liquid Surfaces

Aqueous solutions of potassium chloride were allowed to flow through air. The solutions were from 10-1 N. to 10-7 N. The hydrostatic pressure was from 17 to 22 cm. of solution. The flow was vertical and laminar, through a circular aperture in a thin platinum disc on to a second platinum disc. The diameter of the aperture was 0.05 cm. The discs served as electrodes. The potential difference was measured with a vacuum tube potentiometer. The floating grid method was used, so the potential difference was measured with essentially no current flow. The values obtained were similar to existing data on the streaming potential of such solutions through glass tubes and through cellulose diaphragms

The Diffusions Coefficient of Hemoglobin in Pure Water Solution

Carbon monoxide hemoglobin prepared from beef blood by the method of Marshall and Welker (J. Am. Chem. Soc., 35, 820. 1913) was allowed to diffuse from a water solution of constant concentration into pure pater contained in a thin flat cell of optical glass

The Effect of Egg Albumin on the Solubility of Thallous Salts at 25 C

The solubilities of TlCl, TlCNS, and Tl2SO4, were determined in solutions of egg albumin at 25°C. The Tl+ was titrated to Tl+++ with standard KI03 using the ICl endpoint. The albumin concentration was determined by a modified Kjeldahl method. The pH of each solution was obtained with a glass electrode using M/20 potassium acid phthalate as a standard (pH= 3.97). In solutions of egg albumin dialyzed free of chlorides and sulphates and adjusted to a pH of 3.3 it was found that the greater the albumin concentration the greater was the amount of dissolved salt per 1000 g. of water. In albumin solutions at a pH of about 6 and to which no acid had been added a similar phenomenon was observed except that at small albumin concentrations the solubility of Tl2SO4 was less than in pure water. In dilute isoelectric albumin solutions all three salts studied were less soluble per 1000 g. of water than in pure water. These curves passed through a minimum and in some of the more concentrated albumin solutions the solubility became greater than in pure water. The valence and extent of hydration of the albumin cation was estimated from the solubility of TlCl at a pH of 3.3

The Effect of Gelatin on the Solubility of Thallous Salts in Water

The solubilities of thallous salts were determined in various concentrations of solutions of iso-electric gelatin by saturating the gelatin solution with the salt at 40°C., filtering, and analyzing the solution for thallium and nitrogen content. From these analyses the concentrations of gelatin, water and salt were calculated

The Thickness of a Rigid Water Layer on Quartz From Measurements of Newton\u27s Rings (Abstracts)

Newton\u27s rings produced by a quartz plate and lens in a slit source of light were observed in a low power traveling microscope. The square of the radius of the rings ( r) plotted against the order of the ring ( n) from the center yields a straight line whose intercept on the axis where n = 0 is shown to be a function of the vertical separation of the lens and plate but not a function of the index of refraction of the medium between them nor the angle of incidence of the light. The ring radii were measured with air and with water between the lens and plate. The graphs for the two cases have different intercepts which is interpreted as indicating a rigid water multilayer between the quartz surfaces of the order of 200 AO in thickness