Conductance and conductivity, Chemistry

Assignment Help:

Conductance and conductivity:

When a field (electric) is put across an aqueous ionic solution by applying a voltage between two parallel plate electrodes, the cations are attracted towards to the negative plate (cathode) and the anion towards the positive plate (anode). This movement of ion in a field is called migration and the movement of charge results in a current in the electric circuit connecting the electrodes. The field between the plates is initially linear and produces a constant ion velocity at all points. If there is no redox reaction, cations and anions will separate and collect at the cathode and anode respectively with time, balancing the electrode charge and there will be fewer ions in the bulk of solution. This is a process known as concentration polarization which also leads to the modification of the original linear potential profile between the two electrodes and a variation of ion velocity between the plates. The current will also fall with time. Concentration polarization is therefore useful when separating ions is define, such as in electrophoresis and electro osmosis, but that is to be avoided when measuring fundamental ion motion.

1205_molar conductance.png

Fig. 1. The effect of an AC voltage on the ion motion as electrode polarity is switched.

The ions then alternately migrate first to one plate and then the other during cycling, so that the ions oscillate around a fixed position, avoiding concentration polarization.


Related Discussions:- Conductance and conductivity

Derivation of Ideal gas equation from the kinetic theory, Derivation of Ide...

Derivation of Ideal gas equation from the Kinetic theory

what is aldehyde? , Aldehyde is a carbonyl compound in which one valency o...

Aldehyde is a carbonyl compound in which one valency of carbonyl carbon is satisfied by hydrogen atom and other by a alkyl group.

Reaction intermediates, Reaction Intermediates Short lived fragments th...

Reaction Intermediates Short lived fragments that are known as reaction intermediates result from homolytic and heterolytic bond fission. The significant reaction substances ar

Semiconductor, variation of cnductivigy with temperature

variation of cnductivigy with temperature

CALORIMETRY, when a 0.800g sample of CaCl2 is dissolved in 9.85g of water i...

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 degrees celcius to 35.8 degrees celcius.calc

Origin of charge on colloidal sol, Colloids are either positively charged o...

Colloids are either positively charged or negatively charged. But What are the various factors responsible for charge on the colloidal sols?

Hydrocarbon, markonise and anti markonise

markonise and anti markonise

Thermodymanics, how to use the heat of fusion in a equation

how to use the heat of fusion in a equation

Types of addition reactions, Types of addition reactions Addition react...

Types of addition reactions Addition reactions can be categorized into three categories on the basis of the nature of initiating species. (A) Electrophilic additions (B)

What is nucleophile?, A nucleophile is a chemical species that donates an e...

A nucleophile is a chemical species that donates an electron pair to an electrophile to form a chemical bond in a reaction. All molecules or ions with a free pair of electrons or a

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