The reduction potential values are given below. Which is the strongest reducing agent? $Al^{3+}/Al = -1.67 \, V, Mg^{2+}/Mg = -2.34 \, V, Cu^{2+}/Cu = +0.34 \, V, I_2/2I^- = +0.53 \, V$

Given the standard reduction potentials at $25\,^oC$ for the following half-reactions:
$Zn^{2+}_{(aq)} + 2e^- \rightleftharpoons Zn_{(s)}, E^o = -0.76\,V$
$Cr^{3+}_{(aq)} + 3e^- \rightleftharpoons Cr_{(s)}, E^o = -0.74\,V$
$2H^+_{(aq)} + 2e^- \rightleftharpoons H_{2(g)}, E^o = 0.00\,V$
$Fe^{3+}_{(aq)} + e^- \rightleftharpoons Fe^{2+}_{(aq)}, E^o = +0.77\,V$
Which of the following is the strongest reducing agent?

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

The correct order of reduction potentials of the following pairs is
$A.$ $Cl_2 / Cl^{-}$
$B.$ $I_2 / I^{-}$
$C.$ $Ag^{+} / Ag$
$D.$ $Na^{+} / Na$
$E.$ $Li^{+} / Li$
Choose the correct answer from the options given below.

Bubbles of gas $z$ are evolved from a solution containing $x$ and $y$. If the order of reduction potential is $x > y > z$,then:

What is $emf$?