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

Why is an external $emf$ of more than $2.2 \ V$ required for the extraction of $Cl_2$ from brine?

An electrochemical cell is set up as follows: $Pt(H_2, 1 \, atm) | 0.1 \, M \, HCl || 0.1 \, M \, CH_3COOH | (H_2, 1 \, atm) Pt$. The $E.M.F.$ of this cell will not be zero because:

Give true $(T)$ and false $(F)$ for the following statements:
$(1)$ In a Daniell cell,$Zn$ is dissolved in the solution and $Cu$ is deposited.
$(2)$ In a Daniell cell,when an external $1.1 \ V$ potential is applied in the opposite direction,the reaction stops and no current flows.

For a $Ag-Zn$ button cell,the net reaction is $Zn_{(s)} + Ag_{2}O_{(s)} \rightarrow ZnO_{(s)} + 2Ag_{(s)}$. Given $\Delta G_{f}^{o}(Ag_{2}O) = -11.21 \ kJ \ mol^{-1}$ and $\Delta G_{f}^{o}(ZnO) = -318.3 \ kJ \ mol^{-1}$,the $E^{o}_{cell}$ of the button cell is ......... $V$.

Assertion: The cell potential of a mercury cell is $1.35 \ V$,which remains constant.
Reason: In a mercury cell,the electrolyte is a paste of $KOH$ and $ZnO$.