Complete the electronic configuration for the iron atom and the iron ion in the $+3$ oxidation state. Iron atom: $[\text{Ar}]\ \ldots\ldots\ldots\ldots$. Iron ion in the $+3$ oxidation state: $[\text{Ar}]\ \ldots\ldots\ldots\ldots$.
What does the term homogeneous catalyst mean?
Give an equation for the overall reaction between $\text{S}_2\text{O}_8^{2-}(aq)$ and $\text{I}^-(aq)$.
Suggest why, without a catalyst, the activation energy for this reaction is high.
Write two equations to show how $\text{Fe}^{3+}(aq)$ ions can catalyse the reaction between $\text{S}_2\text{O}_8^{2-}(aq)$ ions and $\text{I}^-(aq)$ ions.
What is meant by the term entropy?
Calculate the standard entropy change, $\Delta S^\circ$, for the reaction $\text{Fe}_2\text{O}_3(s) + 3\text{CO}(g) \rightarrow 2\text{Fe}(s) + 3\text{CO}_2(g)$ using the standard entropies given: $S^\circ(\text{Fe}_2\text{O}_3(s)) = +90$, $S^\circ(\text{CO}(g)) = +198$, $S^\circ(\text{Fe}(s)) = +27$, $S^\circ(\text{CO}_2(g)) = +214\ \text{J K}^{-1}\text{mol}^{-1}$. $\Delta S^\circ = \ldots\ldots\ldots\ \text{J K}^{-1}\text{mol}^{-1}$.
Calculate the standard Gibbs free energy change, $\Delta G^\circ$, for this reaction at $25^\circ\text{C}$. $\Delta G^\circ = \ldots\ldots\ldots\ \text{kJ mol}^{-1}$.
Suggest why a temperature of $1000^\circ\text{C}$ is normally used for this reaction, even though the reaction is spontaneous (feasible) at $25^\circ\text{C}$. Explain your answer.