LAWS OF ELECTROLYSIS

LAWS OF ELECTROLYSIS

     Michael Faraday is the first scintist to investigate the relation between the amount of products formed at electrodes and the electric current passing through the electrolyte.
 
     He observed that the amount of products formed at electrode is direct proportional to the quantity of electric passing through electrolytes.

    From his observation summarized what is commonly known as Faraday's laws of electrolysis.

FARADAY'S FIRST LAW OF ELECTTOLYSIS

Faraday's observed that the quantity of a substance produced at an Electrode during electrolysis depends on three factors, which are;

     - the quantity of electricity passing through the electrolyte per unit time.
    - the amount of time taken by an electric current to pass through electrolyte.
    - the charge on an ions.

The first farady's law of electrolysis state that;
     "The mass of substance produced or dissolved at an Electrode during electrolysis is proportional to the quantity of electricity transferred at electrode".

                                                         

     

     NB;
           Current is measured in an Empire (A).
           Time measured in second (S).
          Electric charge measured in coulombs (C)

When a current passing through a electrolyte at a given time, then electric charge that passes is;
   
                   Q = It
Where; Q = is quantity of electric passed
              I = is current passed through electrolyte
              t = is time taken by current to pass through electrolyte.

If m is mass deposited, then Faraday' first law of electrolysis can be expressed as;

            m = ZIt
     Where Z is constant known as electrochemical equivalent.
                 -    From the formula, m= ZIt
                 -        Z = m/It
                 -     And        It = Q, .          then   Z = m/Q
                 -    SI Unit of Q is C
                 -    there fore unit of Z is g/C .

-- The electrochemical equivalent (Z) of substance is the mass of the substance discharged when 1 coulombs of electricity passing through an electrolyte.

FARADAY'S COSTANT.

 Is the amount of electric charge carried by one mole of electrons.
   The charge on one mole of electrons is approximately to 96 500C. This is the Faraday's constant.

FARADAY'S SECOND LAW OF ELECTTOLYSIS.

FARADAY'S second law state that;
 " When the same quantity of electrolysis is passed through solution of different electrolytes, the mass of substance libareted or deposited at the electrodes is directly proportional the chemical equivalent of the substance".

 This means,  m1 = E1...........(i)
             And,   m2 = E2.............(ii)
Then devide eqn i by eqn ii
              m1/m2 = E1/E2

Where m1 and m2 are the respective masses of substance liberated or deposited on electrodes.

           E1 and E2 are chemical equivalent of the two substance respectively.

NOTE;

           The chemical equivalent of a substance is a relative atomic mass of substance divided by the number of electrons required to oxidize or reduces each unit of the substance.

                                Chemical equivalent = R.A.M/number of charges on an ion.