CBSE 2022 · Region 5 · Set 1 · Q7 · 3 marks
(a)Write any two consequences of Lanthanoid Contraction.(b)Name the element of 3d series which exhibits the largest number of oxidation states. Give reason.
(a)
Write any two consequences of Lanthanoid Contraction.
(b)
Name the element of 3d series which exhibits the largest number of oxidation states. Give reason.
Marking-scheme solution
(a) (i) Similarity in the size of the atoms of the elements belonging to same group of \(\displaystyle 2^{\text {nd }} / 4 \mathrm{~d}\) and \(\displaystyle 3^{\text {rd }} / 5 \mathrm{~d}\) transition series / the second and the third \(\displaystyle d\) series exhibit similar atomic / ionic radii.
(ii) Difficulty in separation of Lanthanoids in pure state.
(iii) Similar physical and chemical properties.
(iv) Basic character of the lanthanide hydroxides \(\displaystyle \mathrm{M}(\mathrm{OH})_{3}\) decreases with increase in atomic number.
(b) Mn, it has maximum number of unpaired electrons / It has maximum number of electrons that will participate in bonding.
The d-and f-Block ElementsThe LanthanoidsUnderstandshort_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 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.