Standard oxidation potentials $(SOP)$ of four metals $P, Q, R$ and $S$ are $+2.87 \ V, +3.05 \ V, -0.80 \ V$ and $+0.25 \ V$ respectively. The reducing power of these metals is:

Which electrode is used to measure the electrode potential of any electrode?

If standard reduction potentials $(E^0)$ of $(Al^{+3}(aq)|Al(s))$, $(Fe^{+2}(aq)|Fe(s))$, $(Cu^{+2}(aq)|Cu(s))$ and $(Ag^{+1}(aq)|Ag(s))$ are $-1.66 \text{ V}$, $-0.44 \text{ V}$, $+0.34 \text{ V}$ and $+0.79 \text{ V}$ respectively, which of the following reactions is non-spontaneous?

For a cell constructed with $Cu$ and $Ag$ electrodes,which of the following statements is correct regarding the cathode and the standard cell potential $(E_{cell}^{\circ})$?

If the cell potential value is negative for a cell constructed by attaching a standard hydrogen electrode to another half-cell,then the other half-cell will be:
$(i)$ Anode or cathode?
$(ii)$ Positive or negative?
$(iii)$ On left side or right side?

The standard reduction potentials for $Zn^{2+}/Zn$,$Ni^{2+}/Ni$ and $Fe^{2+}/Fe$ are $-0.76 \ V$,$-0.23 \ V$ and $-0.44 \ V$ respectively.
The reaction $X + Y^{2+} \rightarrow X^{2+} + Y$ will be spontaneous when: