How does Hittorf method determine transport number?
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How does Hittorf method determine transport number?
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.
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 is Hittorf number?
(1) Definition: “The fraction of the total current carried by an ion is known as transport number, transference number or Hittorf number may be denoted by sets symbols like t+ and t– or tc and ta or nc and na”.
How can you calculate the transference number using the moving boundary method?
In practice, it is necessary to form one boundary and observe the rote of its movement to measure the transference number of one ion, that of the other ion may then be calculated as t+ + t– = 1. or, t+ = (l x a x c F) / 1000Q.
What is kohlrausch’s law of independent migration of ions?
Kohlrausch’s law of independent migration of ions states that the limiting molar conductivity of an electrolyte can be represented as the sum individual contributions of its cations & anions. The conductivity of a solution decrease with dilution because less ions are present for conduction.
What are ionic mobilities?
Ion mobility (IM) is a gas-phase technique allowing the separation of ions based on their mobility through an inert gas (typically helium or nitrogen) under the influence of an electric field [3–5,6•].
How do I find my transference number?
The transference number is defined as the ratio of the electric current carried by an ionic species of interest (Ii) to the total current carried by all ionic species (Itotal) in the system:(11.3)ti=IiItotalSince the electric current carried by an ion is related to the electrophoretic mobility of the ion, the …
Why KCl is suitable for salt bridge?
In s salt bridge, KCl is used because. it is and electrolyte KCl is found in pure crystalline state in large deposits it is a good conductor of electricity it forms a good jelly with agr-agr.
What do you understand by kohlrausch’s law explain with an example?
Kohlrausch’s law states that the equivalent conductivity of an electrolyte at infinite dilution is equal to the sum of the conductances of the anions and cations. If a salt is dissolved in water, the conductivity of the solution is the sum of the conductances of the anions and cations.
What is kohlrausch’s law explain any two applications of kohlrausch’s law?
Kohlrausch Law refers to an electrolyte’s limiting molar conductivity to its constituent ions. It indicates that an electrolyte’s limiting molar conductivity is equal to the sum of the individual limiting molar conductivities of the cations and anions that make up the electrolyte.
What is Kohlrausch’s law discuss with an example?
This law is popularly known as Kohlrausch law of independent migration of ions. For example, limiting molar conductivity, Λ of sodium chloride can be determined with the knowledge of limiting molar conductivities of sodium ion and chloride ion.
How is kohlrausch law calculated?
Kohlrausch law
- α = Λ/ Ëm∘
- α = dissociation constant.
- Λ = molar conductivity of ion.
- Ëm° = limiting molar conductivity of ion.
How does temperature affect transport number?
Ascend in temperature is the key factor that affects a transport number. The anion transport number, therefore, generally decreases with the increase of temperature. With an increase in temperature, the transport number or transference number of cation and anion comes closer to 0.5.
How do you calculate ionic mobilities?
Ionic mobility formula For an applied potential (V), let the current I flow through the cell. Since the solution obeys Ohm law, I = V/R = λV.
What is the principle of Debye Huckel theory?
The Debye-Hückel theory is based on three assumptions of how ions act in solution: Electrolytes completely dissociate into ions in solution. Solutions of Electrolytes are very dilute, on the order of 0.01 M. Each ion is surrounded by ions of the opposite charge, on average.
