$(i)$ When a copper rod is dipped in $1 \ M$ silver nitrate solution,silver crystals are obtained. $(ii)$ Silver metal does not react with $1 \ M$ zinc nitrate solution. $(iii)$ When zinc metal is dissolved in $1 \ M$ copper sulfate solution,copper metal is displaced. Arrange the three metals in the decreasing order of their reducing power.

Which of the following statements is not correct $:-$

$A$ and $B$ are two metals. The standard reduction potentials of $A^{+}_{(aq)} / A_{(s)}$ and $B^{+}_{(aq)} / B_{(s)}$ are $-0.5 \ V$ and $+0.5 \ V$ respectively. What is the $\log K_C$ value for the following reaction at $298 \ K$?
$A_{(s)} + B^{+}_{(aq)} \rightleftharpoons A^{+}_{(aq)} + B_{(s)}$
(Given: $\frac{2.303 RT}{F} = 0.06 \ V$)

Match the entries from Column $I$ and Column $II$ and choose the correct order.

$A$. Leclanche cell	$1$. Converts energy of combustion into electrical energy
$B$. Fuel cell	$2$. Rechargeable cell
$C$. Ni-Cd cell	$3$. At anode,$Zn \longrightarrow Zn^{2+} + 2e^{-}$

For lead storage battery,pick the correct statements:
$A.$ During charging of battery,$PbSO_4$ on anode is converted into $Pb$.
$B.$ During charging of battery,$PbSO_4$ on cathode is converted into $PbO_2$.
$C.$ Lead storage battery consists of a grid of lead packed with $PbO_2$ as cathode.
$D.$ Lead storage battery has $\sim 38\%$ solution of sulphuric acid as an electrolyte.
Choose the correct answer from the options given below:

Efficiency of the following cell is $84\%$. $A_{(s)} + B^{2+}(aq.) \rightleftharpoons A^{2+}(aq.) + B_{(s)}$; $\Delta H^o = -285 \ kJ$. Then the standard $EMF$ of the cell will be ........... $V$.