Catalysts and alternative reaction pathways

When potassium thiocyanate solution is added to a pale yellow solution containing iron(III) ions, the following equilibrium is established. $\ce{[Fe(H2O)6]^3+(aq) + SCN^-(aq) <=> [Fe(SCN)(H2O)5]^2+(aq) + H2O(l)}$ $\ce{[Fe(H2O)6]^3+(aq)}$ is pale yellow and…

In moist air carbonyl dibromide is slowly hydrolyzed: $\ce{Br2CO(g) + H2O(g) -> CO2(g) + 2HBr(g)}$ (i) Suggest a method of monitoring the progress of this reaction at constant temperature so that its rate can be determined. (ii) Outline two reasons why a…

In the first step, manganese(III) ions formed from the manganate(VII) are complexed by ethanedioate ions. $\ce{[Mn(H2O)6]^3+(aq) + 2C2O4^2-(aq) -> [Mn(C2O4)2(H2O)2]^-(aq) + 4H2O(l)}$ (i) Adding a small amount of manganese(II) sulfate, $\ce{MnSO4(s)}$, at the…

(i) Oil of vitriol, spirit of hartshorn and wood alcohol are old trivial names still occasionally used for chemical substances, and names like these can be a source of confusion in international scientific communication. Outline how the modern system of naming…

(i) Sketch the Maxwell–Boltzmann energy distribution curve for the particles in this reaction mixture. Label the activation energy with and without the catalyst on the diagram. (ii) On the same axes, sketch and label a second Maxwell–Boltzmann curve for this…

The forward reaction is endothermic, uses platinum as a catalyst, and takes place at 800 K. Sketch the reaction's energy profile both with and without the catalyst present, labelling the activation energies and $\Delta H$.