What happens to the oxidation number of $Mn$ during the operation of a dry cell?

Calculate $\Delta G^{\circ}$ for the reaction $Mg_{(s)} + Sn_{(aq)}^{2+} \longrightarrow Mg_{(aq)}^{2+} + Sn_{(s)}$ if $E_{cell}^{\circ}$ is $2.23 \ V$. (in $kJ$)

If the salt bridge between two half-cells is removed,the voltage of the cell:

Which of the following reactions is used to make a fuel cell?

Copper displaces which of the following metals from their salt solutions?

Which of the following statements is correct regarding the cathode of an electrochemical cell?