Given that $Ni^{2+}/Ni = -0.25 \ V$; $Cu^{2+}/Cu = 0.34 \ V$; $Ag^{+}/Ag = 0.80 \ V$; $Zn^{2+}/Zn = -0.76 \ V$. Which of the following reactions under standard conditions will not take place in the specified direction?

Consider the following electrochemical cell at standard condition: $Au_{(s)} | QH_2, Q | NH_4X(0.01 \ M) || Ag^{+}(1 \ M) | Ag_{(s)}$. Given $E_{\text{cell}} = +0.4 \ V$. The couple $QH_2 / Q$ represents the quinhydrone electrode,and the half-cell reaction is given as: $Q + 2e^- + 2H^+ \rightarrow QH_2$ with $E^o_{Q/QH_2} = +0.7 \ V$. Given: $E^o_{Ag^+/Ag} = +0.8 \ V$ and $\frac{2.303 \ RT}{F} = 0.06 \ V$. The $pK_b$ value of the ammonium halide salt $(NH_4X)$ used here is $.........$ (nearest integer).

Which of the following statements is not correct $:-$

The number of incorrect statements from the following is:
$A.$ The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.
$B.$ $E_{cell}^0$ is dependent on the pressure.
$C.$ $\frac{dE_{cell}^0}{dT} = \frac{\Delta_{r}S^0}{nF}$.
$D.$ $A$ cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.

Which of the following statements is not correct?

At $300 \ K$,the $E_{cell}^{\circ}$ of $A_{(s)} + B^{2+}_{(aq)} \rightleftharpoons A^{2+}_{(aq)} + B_{(s)}$ is $1.0 \ V$. If $\Delta_r S^{\circ}$ of this reaction is $100 \ J \ K^{-1} \ mol^{-1}$,what is $\Delta_r H^{\circ}$ (in $kJ \ mol^{-1}$) of this reaction? $(F = 96500 \ C \ mol^{-1})$