Equivalent Conductivity

It is defined as the conducting power of all the ions produced by dissolving one gram equivalent of an electrolyte in solution.
It is expressed as and is related to specific conductance as
(M is Molarity of the solution)

where C is the concentration in gram equivalent per litre (or Normality). This term has earlier been quite frequently used. Now it is replaced by molar conductance. The units of equivalent conductance are

Experimental measurement of conductance

(i) The conductance of a solution is reciprocal of the resistance, therefore, the experimental determination of the conductance of a solution involves the measurement of its resistance.

(ii) Calculation of conductivity: We have seen that conductivity (k)is reciprocal of resistivity , i.e.,

and

where G is the conductance of the cell, l is the distance of separation of two electrodes having cross section area

The quantity is called cell constant and is expressed in Knowing the value of cell constant and conductance of the solution, the specific conductance can be calculated as,

i.e.,