Ion mobility, Chemistry

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.

Posted Date: 7/21/2012 2:21:27 AM | Location : United States







Related Discussions:- Ion mobility, Assignment Help, Ask Question on Ion mobility, Get Answer, Expert's Help, Ion mobility Discussions

Write discussion on Ion mobility
Your posts are moderated
Related Questions
Antibiotics: A chemical substance generated by or derived from living cells that is able of inhibiting the life procedures or even destroying micro-organism is known as Antibio

density of gas is 2.86 ltr.the gas maz be-

A crucial step in the Robinson annelation is the elimation of an aldol adduct to form an enone. The elimination of an aldol product can occur in base (it occurs even more readily i

Define Measuring the equilibrium cell potential? Figure shows how we can use a potentiometer to determine the equilibrium cell potential. Consider Figure (a). Outside the galva

Metamerism - Type of Isomerism This type of isomerism is due to the difference in the nature of alkyl groups attached to the polyvalent atoms or functional set. Metamers always

Line Spectru- A emission spectrum that contains very sharp peaks (Prism Like Structure) , corresponding to transitions between states in free atoms.For example, the line spectrum o

In an electrochemical cell a redox reaction perform in two halves. Electrons are liberated by the oxidation half reaction at one electrode and go through an electrical circuit

Chemical methods - Purification of organic compounds Besides these physical methods, few chemical methods have as well been utilized to separate a mixture of organic compounds.

what are the applications of radioactivity in forensics, agriculture, medicine, engineering, and geology

Q. Describe Subatomic Particles and the Nuclear Atom? One of the most significant results of Dalton's theory was that it generally persuaded scientists that atoms exist. As a r