Question

The \(\Lambda_m\) (on y-axis) of \(NaCl\) and \(CsCl\) was plotted against \(\sqrt{c}\) \((c=\text{concentration on x-axis})\). Identify the correct figure for these electrolytes. \[ \Lambda_m=\Lambda_m^\circ-K\sqrt{c} \] Given: \[ \lambda^\circ_{Na^+}=50\; S\,cm^2\,mol^{-1} \] \[ \lambda^\circ_{Cs^+}=77\; S\,cm^2\,mol^{-1} \]

• A. Fig 1
• B. Fig 2
• C. Fig 3
• D. Fig 4

Hint:

For strong electrolytes: \[ \boxed{\Lambda_m=\Lambda_m^\circ-K\sqrt{c}} \] Hence:

• Plot of \(\Lambda_m\) vs \(\sqrt{c}\) is a straight line.

• Intercept at \(\sqrt{c}=0\) gives \(\Lambda_m^\circ\).

• Higher ionic mobility \(\Rightarrow\) higher \(\Lambda_m^\circ\).

Answer 1

The Correct Option is B