Conductivity of electrolytes is measured by using conductivity cell which contains two electrodes separated by a fixed distance \(‘l’\) and have an area of cross-section \(A\) The resistance R of conductivity cell is given by the relation

\[R = \frac{\rho l}{A} = \frac{l}{\kappa A}\]

The quantity \(l/A\) for a particular conductivity cell is constant denoted by \(G^*\) and is called cell constant. The cell constant can be determined by using a \(KCl\) solution whose conductivity is known accurately at various concentrations. The cell constant \(G^* = l / A = R\kappa\). The conductances of different solutions can be determine by using Wheatstone bridge principle.  The specific conductance of a solution k is given by

\[\kappa =\frac{G}{R}\]

The total conductance of the solution is the product of specific conductance and volume of the solution \(\kappa × V\). If the amount of electrolyte dissolved in solution is equal to the gram equivalent weight of the electrolyte, then the total conductance is known as equivalent conductance

\[\Lambda ­eq = 1000K /C\],

where C is the concentration of solution in gram equivalents per litre.

The unit of equivalent conductivity is ­\(\Omega^{−1}cm^2 eq^{−1}\) or \(Scm^2eq^{−1}\). If the amount of electrolyte dissolved in solution is equal to the gram molecular weight of electrolyte, then the total conductance is known as molar conductivity \((\Lambda_M)\).

The unit of molar conductivity is ­­\(\Omega^{−1}cm^2 mol^{−1}\). According to SI system, molar conductance is expressed

as \(S m^2 mol^{−1}\), if concentration is expressed in \(mol\text{ }m^3\). Specific conductance always decreases with the decrease in concentration both for strong and weak electrolytes due to the decrease in the number of ions per unit volume that carry the current in a solution.

Weak electrolytes are only partly associated with solutions. The degree of dissociation of weak electrolytes in an aqueous solution

is inversely proportional to the initial concentration of the electrolyte

The degree of dissociation of weak electrolytes is inversely proportional to the initial concentration of the electrolyte. So the answer is (1).

Option (2) is incorrect because the degree of dissociation is inversely proportional, not directly proportional, to the initial concentration.

Option (3) is incorrect because the degree of dissociation does depend on the initial concentration.

Option (4) is incorrect because the degree of dissociation does not depend on the equilibrium concentration.

The degree of dissociation of a weak electrolyte is the fraction of the molecules in solution that are dissociated into ions. As the initial concentration of the electrolyte increases, the degree of dissociation decreases. This is because the ions in solution are more likely to interact with each other and form molecules, which decreases the number of dissociated ions