Q.Explain the catalytic property of transition metals with two named industrial examples.

Transition metals are effective catalysts because of two structural features working together: their variable oxidation states, which let a metal ion accept electrons from one reactant and donate them to another (forming an unstable intermediate and then regenerating its original state), and their large surface area (in finely divided or oxide form), which lets reactant molecules adsorb onto the metal, weakening their bonds and lowering the activation energy for reaction.

The Contact process. In the industrial manufacture of sulfuric acid, sulfur dioxide is oxidized to sulfur trioxide over a vanadium(V) oxide, $\text{V}_2\text{O}_5$, catalyst:

Vanadium cycles between its $+5$ and $+4$ oxidation states during the catalytic cycle -- $\text{V}_2\text{O}_5$ first oxidizes $\text{SO}_2$ to $\text{SO}_3$ while itself being reduced to $\text{VO}_2$ (vanadium $+4$), and the resulting $\text{VO}_2$ is then re-oxidized back to $\text{V}_2\text{O}_5$ by atmospheric oxygen, ready to catalyse the next cycle. This is a direct illustration of variable-oxidation-state catalysis.

The Haber process. In the industrial manufacture of ammonia, nitrogen and hydrogen are combined directly over a finely divided iron catalyst (promoted with small amounts of $\text{K}_2\text{O}$ and $\text{Al}_2\text{O}_3$ to increase its surface area and activity):

$\text{N}_2 + 3\text{H}_2 \xrightarrow{\text{Fe}} 2\text{NH}_3$ …

Name two standard industrial examples (Contact process/V2O5, Haber process/Fe), give the balanced equation for each, and explain the mechanism (oxida …

Naming the catalyst without the reaction it catalyses, or vice versa; conflating the two mechanisms (oxidation-state cycling and surface a …