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

Food scince, what is the significance of BR in ghee?

what is the significance of BR in ghee?

Illustrate classification of matter, Q. Illustrate Classification of Matter...

Q. Illustrate Classification of Matter? Pure Substances In order to understand what a pure substance is, you must think of it on an atomic level. Elements and compounds

Zone refining, explain zone refining method of purification of silicon

explain zone refining method of purification of silicon

Define conclusion rutherford alpha scattering experiment, Rutherford's alph...

Rutherford's alpha particle scattering experiment eventually led to the conclusion that: (1)The point of impact with matter can be precisely determined (2)Electrons occupy s

Determine electron affinity, Q. How to Determine Electron Affinity? An...

Q. How to Determine Electron Affinity? Ans. Electron affinity is the measure of an atom's tendency to form a negative ion. Electron affinity can be measured by the amou

Organic chemistry, synthesis of di and tri substituted benzenes(symmetrical...

synthesis of di and tri substituted benzenes(symmetrical tribromo benzene, 2-amino-5methylphenol, 3-nitro-4-bromobenzoic acid, 3,4-dibromonitrobenzene, 1,2,3-trimethyl benzene) sta

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