Which one of the following graphs between molar conductivity $\left(\Lambda_m\right)$ versus $\sqrt{C}$ is correct?

Using the standard electrode potentials,predict if the reaction between the following is feasible:
$(a) Fe_{(aq)}^{3+} \text{ and } I_{(aq)}^{-}$
$(b) Ag_{(aq)}^{+} \text{ and } Cu_{(s)}$
$(c) Fe_{(aq)}^{3+} \text{ and } Cu_{(s)}$
$(d) Ag_{(s)} \text{ and } Fe_{(aq)}^{3+}$
$(e) Br_{2(aq)} \text{ and } Fe_{(aq)}^{2+}$

$1000 \, mL$ of $1 \, M$ $CuSO_{4(aq)}$ is electrolysed by $9.65 \, A$ current for $100 \, s$ using $Pt$ electrodes. Which statement is incorrect?

$A$ negative $e.m.f.$ for a cell represents:

In a fuel cell,methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is
$CH_3OH_{(l)} + \frac{3}{2} O_{2(g)} \rightarrow CO_{2(g)} + 2H_2O_{(l)}$
At $298 \ K$,standard Gibbs energies of formation for $CH_3OH_{(l)}$,$H_2O_{(l)}$,and $CO_{2(g)}$ are $-166.2$,$-237.2$,and $-394.4 \ kJ \ mol^{-1}$ respectively. If the standard enthalpy of combustion of methanol is $-726 \ kJ \ mol^{-1}$,the efficiency of the fuel cell will be .......... $\%$.

Identify the correct statements from the following:
$(A)$ At $298 \ K$,the potential of a hydrogen electrode placed in a solution of $pH = 10$ is $-0.59 \ V$.
$(B)$ The limiting molar conductivity of $Ca^{2+}$ and $Cl^{-}$ are $119$ and $76 \ S \ cm^2 \ mol^{-1}$ respectively. The limiting molar conductivity of $CaCl_2$ is $195 \ S \ cm^2 \ mol^{-1}$.
$(C)$ The correct relationship between $K_{c}$ and $E_{cell}^{0}$ is $E_{cell}^{0} = \frac{2.303 RT}{nF} \log K_{c}$.