Give the electronic configurations 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 $\text{KMnO}_4\text{(aq)}$ is added slowly, with shaking, to an acidified solution of $\text{FeSO}_4\text{(aq)}$ until $\text{KMnO}_4$ is in large excess.
Write the ionic equation for the reaction that takes place.
Using relevant $E^{\circ}$ data from the Data Booklet, explain why acidified solutions of $\text{Fe}^{2+}\text{(aq)}$ are relatively resistant to oxidation by air, whereas a freshly formed precipitate of $\text{Fe(OH)}_2$ is readily oxidised to $\text{FeO(OH)}_3$ in alkaline conditions.
Predict the organic products from the following reactions and draw each structure in the boxes provided. You may choose structural or skeletal formulae. (i) Cyclohexylpropene with hot concentrated $\text{MnO}_4^- / \text{H}^+$. (ii) Alkyl-substituted benzene with hot concentrated $\text{MnO}_4^- / \text{H}^+$. (iii) Dihydroxybenzene derivative with hot $\text{Cr}_2\text{O}_7^{2-} / \text{H}^+$.
Sketch intermediate $E$ in the box above.
Suggest appropriate reagents and conditions for the following: reaction I; reaction II.