Define standard electrode potential. Include the standard conditions used.
Complete the diagram below to show an electrochemical cell made from a $\text{Mg}^{2+}/\text{Mg}$ half-cell and a $\text{MnO}_4^-/\text{Mn}^{2+}$ half-cell. Add labels to your diagram.
Use a positive $(+)$ sign and a negative $(-)$ sign to show the polarity of each electrode in your diagram. Add an arrow together with the symbol $e^-$ to indicate the direction of electron flow in the external circuit.
Calculate the standard cell potential, $E^\circ_{\text{cell}}$, for this cell.
Construct an equation for the cell reaction.
Predict how the cell reaction will change, if at all, when the solution in the $\text{Mg}^{2+}/\text{Mg}$ half-cell is diluted by the addition of a large volume of water. Explain your answer.
A molten magnesium salt is electrolysed for $15.0$ minutes by a constant current. $4.75 \times 10^{22}$ magnesium atoms are formed at the cathode. Calculate the current used.