Question

Assertion: Molar conductivity of a weak electrolyte at infinite solution cannot be determined experimentally.
Reason: Kohlraush’s law helps to find molar conductivity of a weak electrolyte at infinite dilution.

A.Both assertion and reason are correct and Reason is the correct explanation for assertion.
B.Both Assertion and reason are correct and Reason is not the correct explanation for assertion.
C.Assertion is correct but Reason is incorrect.
D.Assertion is incorrect and reason is correct.

Answer 1

Hint: We must know that the conducting power of all the ions made by dissolving one mole of an electrolyte in a solution is called molar conductivity. Kohlraush’s law can be defined as the equivalent conductivity of an electrolyte at infinite dilute is equal to total conductance of the anions and cations.

Complete step by step answer:
We know that molar conductivity of a solution comprises one mole of the electrolyte and it is not constant. It is the conductance unit mole of electrolyte, which is placed between two electrodes of unit cross section or at a separate distance of one-centimeter.
Kohlraush’s law can be defined as the equivalent conductivity of an electrolyte at infinite dilute is equal to total conductance of the anions and cations.
We explain the assertion as molar conductivity of a strong electrolyte at infinite dilution could be calculated by extrapolation as linear plot is obtained. In the case of weak electrolyte, the molar conductivity at infinite solution cannot be measured experimentally and by extrapolation because the plot obtained is not linear, the highest value of molar conductivity at infinite solution cannot be determined.
The dissociation of weak electrolyte keeps rising with dilution and is not finished even with infinite dilution.
The assertion and reason is true but reason is not the correct explanation for assertion.
Hence, option (B) is correct.

Note:
Kohlraush’s law helps in determining the limiting molar conductivity of any electrolytes. Weak electrolytes contain lower molar conductivities and lower degree of dissociation for higher concentration. It is used to calculate the dissolution of salts that are sparingly soluble.