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

Manufacture of acetic acid - quick vinegar process, Manufacture of acetic a...

Manufacture of acetic acid - Quick vinegar process (a) From ethyl alcohol (Quick vinegar process): Vinegar is 6-10% aqueous solution of acetic acid. It is acquired by fermen

Moles!, a tablet of extra strength tylenol contains 5.00x10^2 mg of acetami...

a tablet of extra strength tylenol contains 5.00x10^2 mg of acetaminophen. Calculate the number of moles of acetaminophen present in one tablet of extra strength tylenol?

Anaerobic fermentation of grain , In the anaerobic fermentation of grain th...

In the anaerobic fermentation of grain the yeast Saccharomyces cerevisiae digests glucose from plants to create the products ethanol and propenoic acid by the following overall rea

Organometallic compounds, Alkyl ligands form metal carbon σ bonds. Usually ...

Alkyl ligands form metal carbon σ bonds. Usually they occur in conjunction with other organic ligands or CO, but may be achieved on their own, as in tungsten hexamethyl (1), and

P block, why ionisation energy of aluminium is greater then Ga?

why ionisation energy of aluminium is greater then Ga?

Organic, A crucial step in the Robinson annelation is the elimation of an a...

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

What do you mean by polymerisation isomerism, Q. What do you mean by Polyme...

Q. What do you mean by Polymerisation Isomerism? This term is used to describe compounds having same empirical formula but different molecular compositions. The difference from

Illustrate resonance structures, Illustrate resonance structures that defin...

Illustrate resonance structures that define the electronic structure of benzene. Illustrate the structures of all conceivable disubstituted benzene isomers bearing two

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