Question

Given below are two statements : Statements I : The limiting molar conductivity of $KCl$ ( strong electrolyte ) is higher compared to that of $C{H}_{3}COOH$ (weak electrolyte) . Statements II : Molar conductivity decreases with decrease in concentration of electrolyte In the light of the above statements, choose the most appropriate answer from the options given below :
(JEE MAIN 2021)

• A. Both Statements I and II are false
• B. Both Statements I and II are true
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The correct option is A Both Statements I and II are false

In aqueous soluiton, $H^{+}$ exist as $H_3{O}^{+}$ which is smaller in size than the hydrate ions of $K^{+}$ and $C{l}^{-}$. Thus, limiting molar conductivity of $H^{+}$ is very large compare to $K^{+}$ and $C{l}^{-}$. Hence, limiting molar conductivity of $C{H}_{3}COOH$ is higher than $KCl$. Molar conductivity is the conductance property of a solution containing one mole of the electrolyte. On dilution, the molar conductivity increases. For strong electrolyte it increases due to decreased ion- ion force of attraction. For weak electrolyte it increase due to the increase in the degree of dissociation of the electrolyte. Hence, option (b) is correct.