At 298 K , the following reaction takes place for a cell at the hydrogen electrode

$$ \mathrm{H}^{+}(a q)+e^{-} \longrightarrow \frac{1}{2} \mathrm{H}_2 \text { (1 bar) } $$

The solution pH is 10.0 . What is the hydrogen electrode potential in volts?

$$ \left(\frac{2303 R T}{F}=0.06 \mathrm{~V}\right) $$

The resistance of a conductivity cell filled with 0.1 M KCl solution is $100 \Omega$. If the resistance of the same cell when filled with 0.2 M KCl solution is $520 \Omega$, the molar conductivity of 0.02 M solution (in $\mathrm{S} \mathrm{cm}^2 \mathrm{~mol}^{-1}$ ) is (Given: conductivity of 0.1 M KCl solution $=1.29 \mathrm{Sm}^{-1}$ )

For which of the following the $E^{\ominus}\left(M^{3+} / M^{2+}\right)$ is negative?

If $E_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{\circ}=-0.441 \mathrm{~V}$ and $E_{\mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}}^{\circ}=0.771 \mathrm{~V}$, the standard emf of the cell reaction $\mathrm{Fe}(s)+2 \mathrm{Fe}^{3+}(a q) \longrightarrow 3 \mathrm{Fe}^{2+}(a q)$ is