The pressure of $H_2$ required to make the potential of $H_2$-electrode zero in pure water at $298 \ K$ is

What is the reduction electrode potential (in volts) of a copper electrode when $[Cu^{2+}]=0.01 \ M$ is in a solution at $25^{\circ} C$? $(E^{\circ}$ of $Cu^{2+}/Cu$ electrode is $+0.34 \ V)$

$A$ 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 $V$.

Give the formula to calculate the equilibrium constant $K_C$ of any electrochemical cell.

The $E^{\circ}$ of $M \mid M^{2+} \parallel Cu^{2+} \mid Cu$ is $0.3 \ V$. At what concentration of $Cu^{2+}$ (in $mol \ L^{-1}$),the $E_{\text{cell}}$ value becomes zero?
$\left(\frac{2.303 \ RT}{F} = 0.06\right)$,$\left(\text{Conc. of } M^{2+} = 0.1 \ M\right)$

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