At a temperature of $298 \ K$,the $emf$ of the following electrochemical cell: $Ag_{(s)} | Ag^{+}(0.1 \ M) || Zn^{2+}(0.1 \ M) | Zn_{(s)}$ will be (Given,$E^{\circ}_{cell} = -1.562 \ V$) (in $V$)

The reduction potential of a hydrogen half-cell will be positive if:

One half cell in a voltaic cell is constructed by dipping a silver rod in an $AgNO_3$ solution of unknown concentration,and the other half cell is a $Zn$ rod dipped in a $1 \text{ M}$ solution of $ZnSO_4$. $A$ voltage of $1.60 \text{ V}$ is measured at $298 \text{ K}$ for this cell. What is the concentration of $Ag^+$ ions in terms of $\log x$ (where $x = [Ag^+]$)? Given: $E^\ominus_{Zn^{2+}/Zn} = -0.76 \text{ V}$,$E^\ominus_{Ag^+/Ag} = +0.80 \text{ V}$,and $\frac{2.303RT}{F} = 0.059 \text{ V}$.

The hydrogen electrode is dipped in a solution of $pH = 3$ at $25\,^oC$. The potential of the cell would be ............. $V$ (the value of $2.303\,RT/F$ is $0.059\,V$).

What is the standard free energy change for the cell,having the following cell reaction (in $kJ$)?
$2 Ag_{(aq)}^{+} + Cd_{(s)} \longrightarrow 2 Ag_{(s)} + Cd_{(aq)}^{2+}, E^{\circ}_{cell} = 1.20 \ V$

Consider the single electrode process $2H^{+} + 2e^{-} \rightleftharpoons H_2$ catalyzed by a platinum black electrode in $HCl$ electrolyte. The potential of the electrode is $-0.059 \ V$. What is the concentration of the acid in the hydrogen half-cell if the $H_2$ pressure is $1 \ bar$ (in $M$)?