The Demo Site

1)A pale green gas identified as chlorine is liberated.


2)Silvery white mettalic sodium is formed at cathode. The metal remains liquid because its m.p is only 97.8degree celsius and floats owing to its low density.


Electrolysis of Acqeous sodium chloride;- when a solution of nacl is subjected to electrolysis using unattackable electrodes.


1)Liberation of hydrogen gas at cathode.


2)Liberation of anode gas at anode.Tha overall solution becoming basic due to formation of naoh.


The electrolysis of acqeous solution of electrolytes is some what more complex because of ability of water to be oxidised as well as reduced.


The oxidation reaction for water at anode is





The reduction reaction at cathode for water is





->In acidic solution water is reduced through the reaction.





Therefore inthe electrolysis of acqeous nacl following anodic reactions are possible.








Similarly ay cathode the possible reactions are








Out of these 4 possible reactions experimentally 1st and 4th were found to take place.





Faradays laws of electrolyte;-


1st law;- The amount of any substance that is deposited at an electrode is directly proportional to quantity of electricity passed through the electrolyte.


W is directly proportional to Q


W=ZQ


W=weight in the gram of the substance deposited.


Q=quantity of electricity in coloumbs.


Z is constant called eletro chemical equivalent of the substance deposited.


If Q=1coloumb


W=Z


The electrochemical equivalent of a substance is defined as the weight of substance deposited as the weight of substance deposited by the passage of 1coloumb of electricity.

2nd law;-When the same quantity of electricity flows through different electrolytes the amount

of different substance deposited at the electrode is directly proportional to their equivalent weight .

Conductance;-It is the ease with which the current can flow through a conductor. It is defined as the reciprocal of resistance.

Conductance=1/R

Unit:1/Ohm = Ohm inverse (or) Mho.

Specific resistance;- The resistance of a conductor is directly proportional to length and inversely proportional to the area of cross section of the conductor.

R is directly propportional to l/a

R=pl/a

Where p=a constant called specific resistance

If l=1cm, a=1cm square then R=p so the specific resistance is defined as resistance in home of a substance of 1cm in length and 1cm square in area cross section.

(OR)

It is the resistance ofthe 1cm cube of the material.

Unit: R=pl/a

p=Ra/l

=Ohm cm .

Specific conductance;-The reciprocal of specific resistance . It is denoted by k

k=1/p

Specific conductance is the conductance offered by a unit volume ofthe solution.

Units;-k=1/p

=1/ohm cm

=ohm inverse cm inverse

The unit of k is Mho cm inverse