The $E^{0}_{Red}$ values for $P, Q, R$ and $S$ are $-2.90 \, V, +0.34 \, V, +1.20 \, V$ and $-0.76 \, V$ respectively. The decreasing order of their reactivity is:

The standard reduction potentials at $25^o \text{C}$ for $Li^{+}/Li$,$Ba^{2+}/Ba$,$Na^{+}/Na$,and $Mg^{2+}/Mg$ are $-3.05 \ V$,$-2.73 \ V$,$-2.71 \ V$,and $-2.37 \ V$ respectively. Which of the following is the strongest oxidizing agent?

Can $E_{cell}^o$ or $\Delta_r G^o$ for a cell reaction ever be equal to zero?

Which of the following expressions is correct for the standard Gibbs free energy change?

Give the symbolic representation of the following half-cells (electrodes):
$(i)$ $Zn_{(s)} | Zn^{2+}_{(aq)} (1M)$
$(ii)$ $Cu^{2+}_{(aq)} (1M) | Cu_{(s)}$
$(iii)$ $Pt_{(s)} | H_{2(g)} (1 \text{ bar}) | H^+_{(aq)} (1M)$

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?