JEE Main · 2021 · Shift-ImediumEC-032

Given below are two statements: Statement I: The limiting molar conductivity of KCl (strong electrolyte) is higher…

Electrochemistry · Class 12 · JEE Main Previous Year Question

Question

Given below are two statements:

Statement I: The limiting molar conductivity of KCl (strong electrolyte) is higher compared to that of CH3COOH\mathrm{CH_3COOH} (weak electrolyte). Statement 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:

Options
  1. a

    Statement I is false but Statement II is true

  2. b

    Both Statement I and Statement II are true

  3. c

    Statement I is true but Statement II is false

  4. d

    Both Statement I and Statement II are false

Correct Answerd

Both Statement I and Statement II are false

Detailed Solution

Strategy: Evaluate the statements using Kohlrausch's law and the general laws of electrolytic conductan\ce.

Statement I: The limiting molar conductivity (Λm0\Lambda_m^0) for \ceCH3COOH\ce{CH_3COOH} (391\approx 391) is actually significantly higher than that of \ceKCl\ce{KCl} (150\approx 150) mainly due to the extremely high mobility of \ceH+\ce{H^+} ions. So, Statement I is False.

Statement II: Molar conductivity increases as concentration decreases (dilution). The statement says it "decreases", which is incorrect. So, Statement II is False.

Conclusion: Both statements are false.

Answer: (d) Both Statement I and Statement II are false\boxed{\text{Answer: (d) Both Statement I and Statement II are false}}

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Given below are two statements: Statement I: The limiting molar conductivity of KCl (strong… (JEE Main 2021) | Canvas Classes