Complete the electronic structures for the $\text{Cr}^{3+}$ and $\text{Mn}^{2+}$ ions. $\text{Cr}^{3+}$: $1s^2 2s^2 2p^6 \, \ldots$ ; $\text{Mn}^{2+}$: $1s^2 2s^2 2p^6 \, \ldots$
Describe the observations you would make as dilute $\text{KMnO}_4(aq)$ is added slowly, with shaking, to an acidified solution of $\text{FeSO}_4(aq)$ until the $\text{KMnO}_4$ is in large excess.
Construct the ionic equation for the reaction.
Using relevant $E^\circ$ data from the Data Booklet, explain why acidified solutions of $\text{Fe}^{2+}(aq)$ are fairly resistant to oxidation by air, but a freshly made precipitate of $\text{Fe(OH)}_2$ is readily oxidised to $\text{Fe(OH)}_3$ in alkaline conditions.
Predict the organic products of the reactions below and draw their structures in the boxes provided. You may use either structural or skeletal formulae. The reagents are hot concentrated $\text{MnO}_4^- + \text{H}^+$ and hot $\text{Cr}_2\text{O}_7^{2-} + \text{H}^+$.
Draw intermediate $E$ in the box provided.
Suggest suitable reagents and conditions for reaction I and reaction II.