Given ${E^o}_{Hg^{2+}|Hg_2^{2+}} = 0.9 \ V$ and ${E^o}_{Hg_2^{2+}|Hg} = 0.8 \ V$. Calculate the value of ${\Delta _r}{G^o}$ at $25 \ ^oC$ in $kJ/mol$ for the reaction: $Hg_2^{2+} \to Hg^{2+} + Hg_{(l)}$

Consider an electrochemical cell: $A_{(s)} | A^{n+}(aq, 2 \ M) || B^{2n+}(aq, 1 \ M) | B_{(s)}$. The value of $\Delta H^{\ominus}$ for the cell reaction is twice that of $\Delta G^{\ominus}$ at $300 \ K$. If the emf of the cell is zero,the $\Delta S^{\ominus}$ (in $J \ K^{-1} \ mol^{-1}$) of the cell reaction per mole of $B$ formed at $300 \ K$ is. . . . . . . (Given: $\ln(2) = 0.7, R = 8.3 \ J \ K^{-1} \ mol^{-1}$.)

Given below are the half-cell reactions:
$Mn^{2+} + 2e^{-} \rightarrow Mn; E^{o} = -1.18 \ V$
$2(Mn^{3+} + e^{-} \rightarrow Mn^{2+}); E^{o} = +1.51 \ V$
The $E^{o}$ for $3Mn^{2+} \rightarrow Mn + 2Mn^{3+}$ will be:

The value of $E_1^{\circ}$ is (in $V$)

Which of the following statements is incorrect?

The number of correct statements from the following is :
$A.$ $E_{cell}$ is an intensive parameter.
$B.$ $A$ negative $E^{\Theta}$ means that the redox couple is a stronger reducing agent than the $H^{+}/H_2$ couple.
$C.$ The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.
$D.$ The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.