CBSE 2023 · Region 1 · Set 3 · Q34 · 5 marks
(i)In 3d series, which transition element has positive $\displaystyle \mathrm{E}_{\mathrm{M}^{2+} / \mathrm{M}}$ value and why ?(ii)Name a member of lanthanide series which is well-known to show +$\displaystyle 4$ oxidation state.(b)Give reason :(i)The highest oxidation state is exhibited in oxoanions of transition metals.(ii)$\displaystyle \mathrm{HCl}$ is not used to acidify $\displaystyle \mathrm{KMnO}_{4}$ solution.
(i)
In 3d series, which transition element has positive $\displaystyle \mathrm{E}_{\mathrm{M}^{2+} / \mathrm{M}}$ value and why ?
(ii)
Name a member of lanthanide series which is well-known to show +$\displaystyle 4$ oxidation state.
(b)
Give reason :
(i)
The highest oxidation state is exhibited in oxoanions of transition metals.
(ii)
$\displaystyle \mathrm{HCl}$ is not used to acidify $\displaystyle \mathrm{KMnO}_{4}$ solution.
Marking-scheme solution
(a) (i) Copper, Copper, due to high \(\displaystyle \Delta_{\text {sub }} \mathrm{H}\) and low \(\displaystyle \Delta_{\text {Hyd }} \mathrm{H}\) / The sum of enthalpies of sublimation and ionisation of copper is not balanced by the hydration enthalpy.
(ii) Cerium /Terbium
(b)
(i) Due to ability of oxygen to form multiple bonds with transition metals.
(ii) \(\displaystyle \mathrm{KMnO}_{4}\) being an oxidising agent oxidises HCl to chlorine \(\displaystyle \left(\mathrm{Cl}_{2}\right)\).
The d-and f-Block ElementsGeneral Properties of the Transition Elements (d-Block)Understandlong_answermedium
More from The d-and f-Block Elements
- (i) Silver atom has completely filled d-orbitals in its ground state, it is still considered to be a…2022 · asked 3×
- (i) Describe giving reason which one of the following pairs has the property indicated: (I) Fe or Cu - higher…2026 · asked 3×
- The diamagnetic species is:2025 · asked 3×
- Assertion: Zr and Hf are of almost similar atomic radii. Reason (R): This is due to Lanthanoid contraction.2024 · asked 3×
- (i) When pyrolusite ore is fused with KOH, in presence of air, a dark green coloured product 'A' is obtained…2025 · asked 3×
- The element having [Ar] 3 d^10 4 s^1 electronic configuration is2025 · asked 3×
- From the given E^ values of the first row transition elements, answer the following questions: (i) Why is E…2022 · asked 3×
- Account for the following: (i) Transition metals and their compounds show catalytic activities. (ii) Zn, Cd…2022 · asked 3×
CBSE Class 12 Chemistry past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.