Ion mobility, Chemistry

Assignment Help:

Ion mobility:

Ion mobility is related to molar conductivity by the equations:

723_ion mobolity.png

which allows the mobilities, u+ and u- of the cation and anion to be determined from molar conductivity measurements at and away from infinite dilution. z+ and z- are the formal charges of the cation and anion respectively, so z+F and |z-F| are the magnitudes of the charges on a mole of cations and anions. The mobility is always positive (+) and is a measure of the terminal migration speed of an ion per unit applied electric field. This limiting speed is accelerating due to the field is exactly balanced by the viscous drag of the ions moving through the solution which for a spherical ions lead to the equations:

55_ion mobolity1.png

where e is the charge on the electron (-), so ze is the charge on the ions, η is the viscosity, a constant for any solvents which determines how easy it is for the ion to part the solvent molecule and move through solution and a is the hydrodynamic radius of the solvated ion.

 

H+/OH- mobility:

Hydroxide and Protons ions have anomalously high ionic molar conductivities and mobilities in comparison to all ions, and in particular for their size. That is as a result of the mechanism by which they move through solution, called the Grotthus mechanism (Fig. 1).

 

2320_ion mobolity2.png

Fig. 1. The Grotthus mechanism for (a) H+; (b) OH- ion motion in water. The arrows indicate the concerted proton movement when the field is applied.


Related Discussions:- Ion mobility

The covalency of nitrogen, The covalency of nitrogen in  HNO 3 is: (1...

The covalency of nitrogen in  HNO 3 is: (1) 0   (2) 3    (3) 4                               (4) 5 Ans: 5

Uses of perfluorocarbons - hydrocarbon, Uses of Perfluorocarbons Perflu...

Uses of Perfluorocarbons Perfluorocarbons are good electrical insulators. These have several important uses like: (a) Perfluorocarbons are used as surface coatings, lubrican

The uncertainty in momentum of an electron, The uncertainty in momentum of ...

The uncertainty in momentum of an electron is 1 x10 -5 kg- m/s  . The uncertainty in its position will be (h= 6.62 x 10 -34 kg - m 2 / s): (1) 1.05 x 10- 28 m

Light waves, uses of light waves in chemical areas

uses of light waves in chemical areas

How to define fast reactions, Fast reactions are those reactions that occur...

Fast reactions are those reactions that occur instantaneously. A fast reaction depends upon the reaction rates. These reactions are so fast that they occur as soon as the reactants

Carbon is present as graphite in white cast iron , Cast iron is iron or a f...

Cast iron is iron or a ferrous alloy which has been heated until it liquefies, and is then poured into a mould to solidify. It is usually made from pig iron. The alloy constituents

Concentration ore, how is the material extracted from concentrated ore?

how is the material extracted from concentrated ore?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd