The cells which can be recharged are:

If $6$ batteries are connected in series in a car,and each battery has a potential of $2 \ V$,what is the total voltage of the battery system (in $V$)?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: In equation $\Delta_r G = -nFE_{\text{cell}}$,the value of $\Delta_r G$ depends on $n$.
Reason $R$: $E_{\text{cell}}$ is an intensive property and $\Delta_r G$ is an extensive property.
In the light of the above statements,choose the correct answer from the options given below:

Based on the reaction $\frac{4}{3} \, Al + O_2 \to \frac{2}{3} \, Al_2O_3$,with $\Delta G = -827 \, kJ \, mol^{-1}$ of $Al_2O_3$,what is the minimum $e.m.f.$ required for the electrolysis? $(F = 96500 \, C \, mol^{-1})$

Saturated solution of $KNO_3$ is used to make a 'salt-bridge' because:

Consider a cell given below $Cu \,|\, Cu^{2+} \,|\, | \, Cl^{-} \,|\, Cl_2$,$Pt$. Write the reactions that occur at anode and cathode.