Which one of the following metals cannot evolve $H_2$ from acids,$H_2O$,or from its compounds?

The standard electrode potentials $E^{\circ} (V)$ for $Li^{+} / Li$ and $Na^{+} / Na$ respectively are:

Which of the following will have a standard oxidation potential less than $SHE$?

Calculate $E_{cell}^o$ of the following galvanic cell at $298 \ K$:
$Ca_{(s)} | Ca^{2+}_{(aq)} || Fe^{2+}_{(aq)} | Fe_{(s)}$
Given: $E_{Ca^{2+}/Ca}^o = -2.87 \ V$; $E_{Fe/Fe^{2+}}^o = 0.41 \ V$

Using the standard electrode potential values,which of the following statements $(I, II, III, IV)$ is/are correct?
$Fe^{2+}_{(aq)} + 2e^{-} \rightleftharpoons Fe_{(s)}$ ; $E^o = -0.44 \, V$
$Cu^{2+}_{(aq)} + 2e^{-} \rightleftharpoons Cu_{(s)}$ ; $E^o = +0.34 \, V$
$Ag^{+}_{(aq)} + e^{-} \rightleftharpoons Ag_{(s)}$ ; $E^o = +0.80 \, V$
$I$. Copper displaces iron from $FeSO_4$ solution.
$II$. Iron displaces copper from $CuSO_4$ solution.
$III$. Silver displaces copper from $CuSO_4$ solution.
$IV$. Iron displaces silver from $AgNO_3$ solution.

Which of the following has been universally accepted as a reference electrode at all temperatures and has been assigned a value of zero volt?