Question

Match the reaction in List - I with the catalysts in List - II and types of catalysis in List - III:

List - I	List - II	List - III
(a) Oxidation of ${\text{S}}{{\text{O}}_{\text{2}}}$​ to ${\text{S}}{{\text{O}}_3}$​ in lead chamber	(p) ${\text{NO}}$	(u) Positive catalyst
(b) Synthesis of methanol from ${\text{CO}}$and ${{\text{H}}_2}$​	(q) ${\text{Pt}}$	(v) Poisoned by ${\text{CO}}$
(c) Oxidation of ${\text{CO}}$to ${\text{C}}{{\text{O}}_{\text{2}}}$​	(r) ${{\text{V}}_2}{{\text{O}}_3}$	(w) Heterogeneous
(d) Oxidation of ${\text{N}}{{\text{H}}_3}$​ to ${\text{NO}}$in Ostwald's process	(s) ${\text{Rh}}$	(x) Homogeneous

A.{\text{a}} \to {\text{p}} \to {\text{u & x, b}} \to {\text{r}} \to {\text{u & w, c}} \to {\text{q & s}} \to {\text{ u}}\,\& {\text{v & w,}}\,{\text{d}} \to {\text{q & s}} \to {\text{u & v & w}}
B.{\text{a}} \to {\text{p}} \to {\text{u & x, b}} \to {\text{r}} \to {\text{u & w, c}} \to {\text{q & s}} \to {\text{ u}}\,\& {\text{v & w,}}\,{\text{d}} \to {\text{p}} \to {\text{u & v & w}}
C.{\text{a}} \to {\text{p}} \to {\text{u & x, b}} \to {\text{s}} \to {\text{u & w, c}} \to {\text{q & s}} \to {\text{ u}}\,\& {\text{v & w,}}\,{\text{d}} \to {\text{q & s}} \to {\text{u & v & w}}
D.{\text{a}} \to {\text{r}} \to {\text{x, b}} \to {\text{r}} \to {\text{u & w, c}} \to {\text{q & s}} \to {\text{ u}}\,\& {\text{w & w,}}\,{\text{d}} \to {\text{q& s}} \to {\text{u & v & w}}

Answer 1

List 1 contains the reaction, List 2 contains the catalyst used and List 3 contains information about that catalyst or reaction. During the oxidation of ${\text{S}}{{\text{O}}_{\text{2}}}$ a homogeneous catalyst is used. The synthesis of methanol is done by using a transition metal oxide. In oxidation of ${\text{CO}}$ and ${\text{N}}{{\text{H}}_3}$ we will use the metals as catalysts.

Complete step by step answer:
- The oxidation of Sulphur dioxide to sulphur trioxide occurs in the presence of the catalyst nitric oxide. Both sulphur dioxide and sulphur trioxide are gaseous in nature. The catalyst that is nitric oxide is also gaseous in nature hence the catalyst is homogeneous in nature. The presence of Nitric Oxide increases the rate of reaction and hence it acts as a positive catalyst.
- When we react to carbon monoxide gas with hydrogen gas in the presence of catalyst Vanadium trioxide which is a black solid, then methanol is formed. Both the reactants are in gaseous state whereas the catalyst is in solid state so the catalyst is a heterogeneous catalyst and of course it increases the rate of reaction and is a positive catalyst.
- The oxidation of carbon monoxide to carbon dioxide occurs in the presence of catalysts such as platinum and rhodium. Carbon monoxide is gas and the catalyst are solid metals and hence the catalyst is a heterogeneous catalyst and increases the rate of reaction and hence is a positive catalyst. In the presence of carbon monoxide the catalyst gets poisoned and carbon monoxide inhibit the reaction by occupying the active sites so the catalyst get poisoned by carbon monoxide
- The same thing occurs in case of oxidation of ammonia to the nitrogen monoxide or nitric oxide. During the Ostwald process, the platinum and rhodium are used as a catalyst. They are heterogeneous and positive catalysts. Here also the catalyst gets poisoned if carbon monoxide is present, it deactivates the catalyst completely or partially.

Hence, the correct option is A.

Note:
In Chemistry generally a catalyst is a substance which increases the rate of reaction. It is specifically known as a positive catalyst but there are some catalysts which decrease the rate of reaction they are known as negative catalysts. The catalyst works by reducing the activation energy so that the reactants can easily be converted to product.