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TS EAMCET · Chemistry · Electrochemistry

At \(298 \mathrm{~K}\) the molar conductivities at infinite dilution \(\left(\Lambda_m^{\circ}\right)\) of \(\mathrm{NH}_4 \mathrm{Cl}, \mathrm{KOH}\) and \(\mathrm{KCl}\) are 152.8, 272.6 and \(149.8 \mathrm{~S} \mathrm{~cm} \mathrm{cmol}^{-1}\) respectively. The \(\Lambda_m^{\circ}\) of \(\mathrm{NH}_4 \mathrm{OH}\) in \(\mathrm{S} \mathrm{cm}^2 \mathrm{~mol}^{-1}\) and \(\%\) dissociation of \(0.01 \mathrm{M} \mathrm{NH}_4 \mathrm{OH}\) with \(\Lambda_m=25.1 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}\) at the same temperature are

  1. A \(275.6,0.91\)
  2. B \(275.6,9.1\)
  3. C \(266.6,9.6\)
  4. D 30,84
Verified Solution

Answer & Solution

Correct Answer

(B) \(275.6,9.1\)

Step-by-step Solution

Detailed explanation

\[ \begin{aligned} \Lambda_m^{\circ} \mathrm{NH}_4 \mathrm{OH} & =\Lambda_m^{\circ}\left(\mathrm{NH}_4 \mathrm{Cl}+\mathrm{KOH}\right)-\Lambda_m^{\circ}(\mathrm{KCl}) \\ & =152.8+272.6-149.8 \\ & =275.6 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1} \end{aligned} \] Degree of…