Given the standard electrode potentials $E^{0}_{Fe^{2+}|Fe} = -0.44 \, V$ and $E^{0}_{Fe^{3+}|Fe^{2+}} = 0.77 \, V$. If $Fe^{2+}$,$Fe^{3+}$,and $Fe$ are all present together,then:

Which of the following reactions is possible at the anode?

The correct formula of calomel is:

$A$ button cell used in watches functions as follows:
$Zn_{(s)} + Ag_2O_{(s)} + H_2O_{(l)} \rightarrow 2Ag_{(s)} + Zn^{2+}_{(aq)} + 2OH^{-}_{(aq)}$
If the half-cell potentials are:
$Zn^{2+}_{(aq)} + 2e^- \rightarrow Zn_{(s)} \,;\, E^o = -0.76 \, V$
$Ag_2O_{(s)} + H_2O_{(l)} + 2e^- \rightarrow 2Ag_{(s)} + 2OH^{-}_{(aq)} \,;\, E^o = 0.34 \, V$
The cell potential will be $..........$ $V.$

Write a note on lead storage cell (battery).

Give the uses of the lead storage cell.