State the electrode material used in each half-cell: • $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell • $\text{Al}^{3+}/\text{Al}$ half-cell
Use the Nernst equation to find the electrode potential, $E$, of the $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell under these conditions. The cell runs at $298\ \text{K}$. The $\text{Al}^{3+}/\text{Al}$ half-cell is at standard concentration. The $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell has $[\text{Sn}^{4+}] = 0.300\ \text{mol dm}^{-3}$ and $[\text{Sn}^{2+}] = 0.150\ \text{mol dm}^{-3}$.
Calculate the value of $E_{\text{cell}}$ for these conditions.
Write an equation for the total cell reaction that takes place.
Aluminium is obtained commercially by electrolysing a melt that contains large quantities of $\text{Al}^{3+}$ ions. Calculate the mass of aluminium produced when a current of $300\ 000\ \text{A}$ flows for $24$ hours. Give your answer to three significant figures.
Explain why chromium metal cannot be obtained by electrolysing dilute aqueous chromium(II) sulfate. Your response should include data from the Data Booklet.