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

Hybrisation, examples of spd arrangement

examples of spd arrangement

Nodes of the original 2p orbitals, Both of the MOs have the nodes of the or...

Both of the MOs have the nodes of the original 2p orbitals, which merge into a one node because the nodal plane is common to both orbitals. The antibonding MO has in addition a

Acid-base titrations - titration curves, ACID-BASE TITRATIONS Titratio...

ACID-BASE TITRATIONS Titration curves: An acid-base titration is a useful experimental method for determining also the amount of an unknown acid or base in solution and th

The element having atomic number 14 should, The atom of the element having ...

The atom of the element having atomic number 14 should have: (1) One unpaired electron (2) Two unpaired electrons (3) Three unpaired electrons (4) Four unpaired electr

#lanthaide actinide, why lanthanides and actinides are known as inner trans...

why lanthanides and actinides are known as inner transition elements

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

Lead acetate test, what is the confirmatory test for acid radical(so42-)

what is the confirmatory test for acid radical(so42-)

Density, You are given a sample block of an unknown metal. The block disp...

You are given a sample block of an unknown metal. The block displaces 3.24 mL of water and has a mass of 62.5429 g. What is the density of the unknown metal? What is the metal?

#title.REACTIONA KINETICS, HOW MANY HALF LIVES ARE REQUIRED FOR THE CONCENT...

HOW MANY HALF LIVES ARE REQUIRED FOR THE CONCENTRATION OF REACTANT TO DECREASE BY 1.56 PERCENT OF ITS ORIGINAL VALUE

Visible range of hydrogen spectrum will contain, Visible range of hydrogen ...

Visible range of hydrogen spectrum will contain the following series: (1)  Pfund (2) Lyman (3) Balmer (4) Brackett Ans: Balmer

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