Consider the cell reaction at 300 K .

$$ A(s)+B^{2+}(a q) \rightleftharpoons A^{2+}(a q)+B(s) $$

Its $E^{\ominus}$ is 1.0 V . The $\Delta_r H^{\ominus}$ of the reaction is $-163 \mathrm{kJmol}^{-1}$.

What is $\Delta_r s^{\ominus}$ (in $\mathrm{JK}^{-1}$ ) of the reaction?

$$ \left(F=96500 \mathrm{C} \mathrm{~mol}^{-1}\right) $$

In which of the following Galvanic cells emf is maximum?

(Given, $E_{\mathrm{Mg}^{2+} \mid \mathrm{Mg}}^{\circ}=-2.36 \mathrm{~V}$

and $E_{\mathrm{Cl}_2 \mid 2 \mathrm{Cl}^{-}}^{\circ}=+136 \mathrm{~V}$ )

Consider the following standard electrode potentials ( $E^{\circ}$ in volts) in aqueous solution.

$$ \begin{array}{|c|c|c|} \hline \text { Element } & M^{3+} / M & M^{+} / M \\ \hline \mathrm{Al} & -1.66 & +0.55 \\ \hline \mathrm{TI} & +1.26 & -0.34 \\ \hline \end{array} $$

Based on this data. which of the following statements is correct?

The standard reduction potentials of $2 \mathrm{H}^{+} / \mathrm{H}_2, \mathrm{Cu}^{2+} / \mathrm{Cu}, \mathrm{Zn}^{2+} / \mathrm{Zn}$ and $\mathrm{NO}_3^{-}, \mathrm{H}^{-} / \mathrm{NO}$ are 0.0 0.34 . -0.76 and 0.97 V respectively. Identify the correct statements from the following.

I. $\mathrm{H}^{+}$does not oxidise Cu to $\mathrm{Cu}^{2+}$

II. Zn reduces $\mathrm{Cu}^{2+}$ to Cu

III. $\mathrm{NO}_3^{-}$oxidises Cu to $\mathrm{Cu}^{2+}$