Match the compounds given in List-I with their application given in List-II
|
List-I (compound) |
List-II (Applications) |
|
(A). \( TiO \) |
(I). dry battery cells |
|
(B). \( AgBr \) |
(II). Wacker process |
|
(C). \( MnO_2 \) |
(III). pigment industry |
|
(D). \( PdCl_2 \) |
(IV). photographic industry |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
Besides their use as metals and catalysts, several compounds of the transition elements are made for special purposes, each depending on one property of the compound.
(A) \(TiO\) — This matches (III) pigment industry. Titanium oxide is used in the pigment industry.
(B) \(AgBr\) — This matches (IV) photographic industry. Silver bromide is light-sensitive: light decomposes it to silver, which forms the image on photographic film.
(C) \(MnO_2\) — This matches (I) dry battery cells. In the Leclanché dry cell, \( \ce{MnO2} \) mixed with carbon is reduced at the cathode:
\( \displaystyle \ce{MnO2 + NH4+ + e- -> MnO(OH) + NH3} \)
(D) \(PdCl_2\) — This matches (II) Wacker process. In the Wacker process, palladium(II) chloride catalyses the oxidation of ethene to ethanal:
\( \displaystyle \ce{CH2=CH2 + H2O + PdCl2 -> CH3CHO + Pd + 2HCl} \)
Shortcut: (A)-(III) appears only in Options (3) and (4), and (B)-(IV) then leaves only Option (4).
NCERT (2026-27 edition):
Some Applications of d- and f-Block Elements – “Iron and steels are the most important construction materials. Their production is based on the reduction of iron oxides, the removal of impurities and the addition of carbon and alloying metals such as Cr, Mn and Ni. Some compounds are manufactured for special purposes such as TiO for the pigment industry and MnO2 for use in dry battery cells.”