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

Coordination chemistry, A compound exists in 2 forms. One them produces 2mo...

A compound exists in 2 forms. One them produces 2moles of AgBr while the other produces 1mole of AgBr with AgNO3

Chemical kinetics, Ask question #The first-order rate constant for the deco...

Ask question #The first-order rate constant for the decomposition of dimethyl ether is 3.2 ? 10 -4 s -1 at 450 o C. The reaction is carried in a constant volume flask. Initially on

Explain in detail about the allotropy, Explain in detail about the Allotrop...

Explain in detail about the Allotropy Allotropy refers only to dissimilar forms of an element within the similar phase or state of matter (i.e. different solid, liquid or gas

Salt analysis., CAN I PLEASE GET A SALT ANALYSIS CHART FOR MY CHEMISTRY PRA...

CAN I PLEASE GET A SALT ANALYSIS CHART FOR MY CHEMISTRY PRACTICALS?

Peptide bond through dehydration, how is a peptide bond made through dehydr...

how is a peptide bond made through dehydration using a chemical equation?

Chemistry, when a 0.800g sample of cacl2 is dissolved in 9.85g of water in ...

when a 0.800g sample of cacl2 is dissolved in 9.85g of water in a microscale calorimeter, the temperature of the solution rose from 23.4 to 35.8

Explain what is a base line, Explain What is a base line? Base line is no...

Explain What is a base line? Base line is nothing but the detectors response to the mobile phase.(gc,hplc)

Symmetry operations, what are the symmetry operations of N2O5 and C2H2

what are the symmetry operations of N2O5 and C2H2

Radioanalytical methods, Radioanalytical methods: Radioanalytical meth...

Radioanalytical methods: Radioanalytical methods using radiotracers and activation analysis are more sensitive and specific because of ease of detection of nuclear radiation.

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