Consider the following cell reaction:
$2 Fe_{(s)} + O_{2_{(g)}} + 4 H_{(aq)}^{+} \rightarrow 2 Fe_{(aq)}^{2+} + 2 H_2O_{(l)} \quad E^{\circ} = 1.67 \ V$. At $[Fe^{2+}] = 10^{-3} \ M, P(O_2) = 0.1 \ atm$ and $pH = 3$,the cell potential at $25^{\circ} C$ is (in $V$)

Calculate $pH$ of $HCl$ solution at $298\,K$ temperature for the following cell: $Pt_{(s)} \mid H_2 \,(1\,bar) \mid HCl\,(xM) \parallel Cu^{2+}\,(0.02\,M) \mid Cu_{(s)}$. Given that the standard cell potential $E^{\circ}_{cell} = 0.34\,V$ and the measured cell potential $E_{cell} = 0.45\,V$.

If the concentration of a $Zn^{2+}$ solution is diluted $10$ times,what is the change in the potential of the $Zn/Zn^{2+}$ electrode?

$A$ hydrogen electrode is made by dipping platinum wire in a solution of nitric acid of $pH=9$ and passing hydrogen gas around the platinum wire at $1.2 \ atm$ pressure. The oxidation potential of such an electrode equals $V$.

Calculate the $EMF$ of the cell: $Cr | Cr^{+3}(0.1 \, M) || Fe^{+2}(0.01 \, M) | Fe$
(Given: $E^o_{Cr^{+3}|Cr} = -0.75 \, V$,$E^o_{Fe^{+2}|Fe} = -0.45 \, V$) (in $, V$)

An oxidation-reduction reaction in which $3$ electrons are transferred has a $\Delta G^{\circ}$ of $17.37 \ kJ \ mol^{-1}$ at $25^{\circ} C$. The value of $E_{\text{cell}}^{\circ}$ (in $V$) is........ $\times 10^{-2} \ V$.
$(1 \ F = 96,500 \ C \ mol^{-1})$