What is transport number describes Hittorf method for its determination?
The Hittorf method is an experimental technique for the determination of transport numbers. For the simplest case of a solution of a single salt of univalent ions, the transport numbers are defined as the mobility of the ion divided by the sum of mobilities of the two ions.
What is Hittorf rule?
Hittorf studied such changes experimentally and gave a general rule known as the Hittorf’s Rule. It states that : the loss of concentration around any electrode is proportional to the speed of the ion moving away from it. Hittorf’s Rule may be illustrated by the following scheme.
What are the factors that influence transport number of ions?
Factors influencing the transport number of ions are “variation of transport with concentration”, “variation of transport number with temperature”, “variation of transport number with electrolyte”.
Which of the following methods are used to determine the transport number of ions?
“There are two experimental techniques for the determination of transport numbers. The Hittorf method is based on measurements of ion concentration changes near the electrodes. The moving boundary method involves measuring the speed of displacement of the boundary between two solutions due to an electric current.
How is transport number related to ionic mobility?
The ionic mobility is described as the speed achieved by an ion moving through a gas under a unit electric field. It is denoted by (μ). The unit of ionic mobility is m2s−1 volt−1. Ion transport number (transference number) is the fraction of the total current carried in an electrolyte by a given ion.
What is the transport number of Cl ion?
the transport number of cl- in aqueous solution of HCl is 0.16.
What is kohlrausch’s law?
Definition of Kohlrausch’s law : a statement in physical chemistry: the migration of an ion at infinite dilution is dependent on the nature of the solvent and on the potential gradient but not on the other ions present.
What is transport number of ion explain moving boundary method?
There are two experimental techniques for the determination of transport numbers. The Hittorf method is based on measurements of ion concentration changes near the electrodes. The moving boundary method involves measuring the speed of displacement of the boundary between two solutions due to an electric current.
Which instrument is used to detect the moving boundaries in moving boundary electrophoresis?
On applying voltage, the compounds will migrate to the anode or cathode depending on their charges. The change in the refractive index at the boundary of the separated compounds is detected using Schlieren optics at both ends of the solution in the cell.
What is C in Ostwald dilution law?
(ii) Concentration of any ion = Cα = √CK = √K/V. K =dissociation constant of a weak acid. α = degree of dissociation. Ostwald’s dilution law states that only at infinite dilution the weak electrolyte undergoes complete ionization. 6,820.
Is there a theoretical treatment of the moving boundary method?
The lack of a simple and fairly complete theoretical treatment of the moving boundary method has been felt in this laboratory in the course of transport number measurements in dye solutions. The results of these measurements -are shortly to be published by Dr. C. Robinson and one of us (J. L. M.). In
Is there a connection between erroneous moving boundary measurements and Hittorf method?
Erroneous moving boundary measurements in the literature are criticized, and the theoretical and experimental connection with the Hittorf method is pointed out. VI. It is also shown, though less rigidly than in the case of two pure electro- lytes, that a sharp boundary will usually exist under similar conditions between
What is the significance of the initial concentration of a moving boundary?
of a moving boundary is independent of the initial concentration of the follow- ing (indicator) solution, since in all realizable cases the leading solution remains of constant concentration, and the indicator solution adjusts its concentration to a final constant value.
Is a small correction for volume changes necessary in the moving boundary?
In the moving boundary method a small correctiont for volume changes; is necessary. As this correction has already been fully treated, it will not be taken into consideration in this paper, t.e., a section fixed with respect to the apparatus will be assumed fixed with respect to the solvent.