Which of the following metals will not react with a solution of $CuSO_4$?

What will occur if a block of copper metal is dropped into a beaker containing a solution of $1 \ M \ ZnSO_4$?

$A$ hypothetical electrochemical cell is shown below.
$A \,|\, A^{+} \,(x \ M)\, ||\, B^{+} \,(y \ M)\, |\, B$
The $emf$ measured is $+ 0.20 \ V.$ The cell reaction is

Give the uses of the mercury cell.

In which cell is the free energy of a chemical reaction directly converted into electricity?

$A$ 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 $..........$ $V.$