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

Liebermann nitroso reaction, Liebermann's nitroso reaction While pheno...

Liebermann's nitroso reaction While phenol is reacted with NaNO 2 and concentrated H 2 SO 4 , it provides a deep green or blue colour which changes to red on dilution with wa

Equilibrium constant, What is the effect of the various concentrations of a...

What is the effect of the various concentrations of aniline hydrochloride on the ph and the X value, and what''s the logic behind all this

Periodic elements, What periodic elements are found in computers

What periodic elements are found in computers

Initial radical concentration, (a) Given the values below, Determine the co...

(a) Given the values below, Determine the concentration of benzoyl peroxide needed to prepare polystyrene with a number average molar mass of 400,000 by bulk free radical polymeris

What is the electronic configuration, What is the electronic configuration ...

What is the electronic configuration of Cu 2+ (Z= 29) of least position: (1) [Ar]4s 1 3d 8                   (2)  [Ar]4s 2 , 3d 10 4p 1       (3) [Ar]4s 1 3d 10

Concentration of the enzyme, The concentration of the product in the equili...

The concentration of the product in the equilibrium is enhancing with increasing concentration of the substrate.      ?     ? The concentration of the product in the equilibrium

Electrovalent bond formation depends on, Electrovalent bond formation depen...

Electrovalent bond formation depends on: (1) Ionization energy (2) Electron affinity (3) Lattice energy (4) All the three above Ans:  All the three above

Terminologies in organic chemistry!, (a) Co-ordination compound A co-ordi...

(a) Co-ordination compound A co-ordination compound contains a central metal atom or cation which is surrounded by a suitable number of anions or neutral molecules and usually re

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