Conductance and conductivity, Chemistry

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.

Posted Date: 7/20/2012 4:45:27 AM | Location : United States







Related Discussions:- Conductance and conductivity, Assignment Help, Ask Question on Conductance and conductivity, Get Answer, Expert's Help, Conductance and conductivity Discussions

Write discussion on Conductance and conductivity
Your posts are moderated
Related Questions
The atomic number of an element is always equal to: (1)Atomic weight divided by 2    (2)Number of neutrons in the nucleus   (3)Weight of the nucleus   (4)Electrical ch

Uses of Glucose (a) Glucose is used in the conservation of fruits and making of jams and jellies. (b) Glucose is used in the preparation of confectionary and as a sweetening

what is the defination of interstitial?

feature of s, p, d,f block in periodic table

what is the radis of carvater eassy words

why cerium oxides is less soluble in water?


what the uses of nitro compound in pharmacy

what is conductometry and how it work

how can you relate boyle''s law to atmospheric pressure?