JAMB Chemistry 2024 Paper

Concept:The contact process is the industrial route for manufacturing sulphuric acid, and a specific transition metal oxide speeds up the key oxidation step.Explanation:In the contact process, sulphur(IV) oxide is oxidised to sulphur(VI) oxide.The balanced equation is: $$2\mathrm{SO}_2(g) + \mathrm{O}_2(g) \xrightarrow[\mathrm{V_2O_5}]{} 2\mathrm{SO}_3(g)$$Sulphur(IV) oxide is sulphur dioxide, $\mathrm{SO}_2$.Sulphur(VI) oxide is sulphur trioxide, $\mathrm{SO}_3$.The catalyst used is vanadium(V) oxide, $\mathrm{V}_2\mathrm{O}_5$.This catalyst works well under the conditions of about $450\,{}^{\circ}\mathrm{C}$ and $1\text{–}2$ atm pressure.It is preferred over platinum because it is cheaper and is not easily poisoned by arsenic impurities in the sulphur feedstock.Answer:C. vanadium(V) oxide ($\mathrm{V}_2\mathrm{O}_5$).