Match the items given in List-I with items given in List-II
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List-I |
List-II |
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(A) Interstitial Compounds |
(I) Large number of complex |
|
(B) Alloy formation |
(II) Chemically inert |
|
(C) Transition metals |
(III) Ni |
|
(D) Catalytic hydrogenation |
(IV) Blend of different metals |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
The items are characteristic properties of the transition elements. Most of them come from their small atomic size, high nuclear charge and partly filled d orbitals.
(A) Interstitial Compounds — This matches (II) Chemically inert. Interstitial compounds form when small atoms such as H, C or N are trapped in the spaces of the metal crystal lattice, as in TiC, \( \ce{Mn4N} \) and \( \ce{Fe3H} \). They are usually non-stoichiometric, very hard, have high melting points, keep metallic conductivity and are chemically inert.
(B) Alloy formation — This matches (IV) Blend of different metals. An alloy is a blend of metals. Transition metals have similar atomic radii, so atoms of one metal can take the place of another in the lattice; brass (Cu–Zn), bronze (Cu–Sn) and the many steels are examples.
(C) Transition metals — This matches (I) Large number of complex. Their small, highly charged ions and vacant d orbitals that can accept lone pairs from ligands make them form a large number of complexes, such as \( \ce{[Fe(CN)6]^4-} \) and \( \ce{[Cu(NH3)4]^2+} \).
(D) Catalytic hydrogenation — This matches (III) Ni. Finely divided nickel adsorbs hydrogen on its surface and catalyses its addition to C=C bonds, as in the hardening of vegetable oils:
\( \displaystyle \ce{CH2=CH2 + H2} \xrightarrow{\ce{Ni},\ \Delta} \ce{CH3-CH3} \)