Which reactions are possible due to electro-chemistry in human brain?

Which of the following statements is incorrect?

Calculate the equilibrium constant at $298 \ K$ for the following reaction and also calculate the maximum work that can be obtained from this cell:
$Mg(s) \ | \ Mg^{2+}(aq) \ || \ Ag^{+}(aq) \ | \ Ag(s)$
Given: $E_{Mg^{2+} \mid Mg}^{o} = -2.37 \ V$ and $E_{Ag^{+} \mid Ag}^{o} = 0.80 \ V$

Given that $E^o_{Fe^{2+}/Fe} = -0.44 \ V$,$E^o_{Cu^{2+}/Cu} = 0.34 \ V$,and $E^o_{Ag^+/Ag} = 0.80 \ V$. Which of the following statements is correct?

$A$ and $B$ are two metals. The standard reduction potentials of $A^{+}_{(aq)} / A_{(s)}$ and $B^{+}_{(aq)} / B_{(s)}$ are $-0.5 \ V$ and $+0.5 \ V$ respectively. What is the $\log K_C$ value for the following reaction at $298 \ K$?
$A_{(s)} + B^{+}_{(aq)} \rightleftharpoons A^{+}_{(aq)} + B_{(s)}$
(Given: $\frac{2.303 RT}{F} = 0.06 \ V$)

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