Question

Match the metals/ions/compounds given in Column-I with the reactions where they act as catalyst as given in Column-II. \[ \begin{array}{llll} (a) & V_2O_5 & (p) & \text{Synthesis of ammonia by Haber's process} \\[6pt] (b) & \text{Fe powder} & (q) & \text{Hydrogenation of alkene} \\[6pt] (c) & Fe^{3+} & (r) & \text{Manufacture of } H_2SO_4 \text{ by Contact Process} \\[6pt] (d) & \text{Ni(s)} & (s) & \text{Oxidation of } I^- \text{ by } S_2O_8^{2-} \end{array} \]

• A. \((a)-(s),\ (b)-(r),\ (c)-(q),\ (d)-(p)\)
• B. \((a)-(r),\ (b)-(s),\ (c)-(p),\ (d)-(q)\)
• C. \((a)-(s),\ (b)-(q),\ (c)-(r),\ (d)-(p)\)
• D. \((a)-(r),\ (b)-(p),\ (c)-(s),\ (d)-(q)\)

Hint:

\[ \begin{aligned} V_2O_5 &: \text{Contact Process} \\ \text{Fe} &: \text{Haber Process} \\ \text{Ni} &: \text{Hydrogenation of alkenes} \\ Fe^{3+} &: \text{Catalyst for } I^- + S_2O_8^{2-} \end{aligned} \]

Answer 1

The Correct Option is D

Step 1: Understand the task.
We have to pair each catalyst with the reaction where it is actually used. The cleanest way is to recall one fixed fact for each catalyst and eliminate options.

Step 2: Vanadium pentoxide.
$V_2O_5$ is the standard catalyst in the Contact Process for making $H_2SO_4$. So $(a)$ pairs with $(r)$.

Step 3: Iron powder.
Finely divided iron is the catalyst in Haber's process for ammonia. So $(b)$ pairs with $(p)$.

Step 4: Ferric ion.
$Fe^{3+}$ catalyses the oxidation of iodide ion by peroxodisulphate, a classic homogeneous catalysis example. So $(c)$ pairs with $(s)$.

Step 5: Nickel.
Solid nickel is used to hydrogenate alkenes (and oils). So $(d)$ pairs with $(q)$.

Step 6: Match the option.
The set is $(a)-(r), (b)-(p), (c)-(s), (d)-(q)$, which is the fourth option.
\[ \boxed{(a)-(r),\ (b)-(p),\ (c)-(s),\ (d)-(q)} \]