# 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., _{}