Question

The molar conductivity is maximum for the solution of concentration?
A) $0.004M$
B) $0.002M$
C) $0.005M$
D) $0.001M$

Answer 1

We need to know that molar conductivity can also be defined as the conducting power of all the ions that are formed by dissolving a mole of electrolyte in a solution. Molar conductivity is the property of an electrolyte solution that is mainly used in determining the efficiency of a given electrolyte in conducting electricity in a solution. It is therefore not a constant.

Complete answer:
As we know, molar conductivity is defined as the conductivity of an electrolyte solution divided by the molar concentration of electrolyte.
We know the relation between Molar conductivity and Molarity i.e.
${\Lambda _m} = \dfrac{K}{C}$
Where K is the specific conductivity and c is the concentration in mole per litre.
For strong electrolytes, the increase in concentration produces a sharp increase in conductivity. However, at lower concentration weak electrolytes poses very low values of specific conductivity and the value gradually increases as the concentration is increased. In general, the molar conductivity of an electrolytic solution is the conductance of the volume of the solution containing a unit mole of electrolyte that is placed between two electrodes of unit area cross-section or at a distance of one-centimeter apart.
The unit of molar conductivity is $S \cdot {m^2} \cdot mo{l^{ - 1}}$.
Hence, the solution having maximum molar conductivity has to be less concentrated.

Thus the correct option for this question will be option D.

Note:
We need to know that the molar conductivity of both weak and strong electrolytes increases with a decrease in concentration or dilution. We know that the molar conductivity is the conductivity offered by one mole of ions. Even after dilution, we are still considering the same unit mole of ions.