✓ Board-verified
Chemistry · 2022 · 3 marks
The d-and f-Block ElementsGeneral Properties of the Transition Elements (d-Block)3 marksUnderstandshort answer
CBSE 2022 · Region 5 · Set 2 · Q8
Give reasons for the following statements: (a) Scandium ( Z =21) is a transition element but Zn ( Z =30) is not. (b) [ Ti ( H_2 O )]^3+ is coloured…
Give reasons for the following statements :
(a)
Scandium $\displaystyle (\mathrm{Z}=21)$ is a transition element but $\displaystyle \mathrm{Zn}(\mathrm{Z}=30)$ is not.
(b)
$\displaystyle \left[\mathrm{Ti}\left(\mathrm{H}_{2} \mathrm{O}\right)\right]^{3+}$ is coloured while $\displaystyle \left[\mathrm{Sc}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$ is colourless.
(c)
Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar than expected.
Marking-scheme solution
(a) Sc has incompletely filled 3d-orbital in its ground state but Zn atom has completely filled \(\displaystyle d\)-orbitals in its ground state as well as in its oxidised state.
(b) Due to \(\displaystyle d-d\) transition of electron in \(\displaystyle \mathrm{Ti}^{3+}\) but no d-d transition in \(\displaystyle \mathrm{Sc}^{3+}\) / Due to presence of unpaired electron in \(\displaystyle \mathrm{Ti}^{3+}\) while \(\displaystyle \mathrm{Sc}^{3+}\) does not have unpaired electrons.
(c) Due to lanthanoid contraction / due to poor shielding effect of 4f orbitals.
All The d-and f-Block Elements questions2022 question paperNCERT solutions: The d-and f-Block ElementsPractice The d-and f-Block Elements →
More from The d-and f-Block Elements
- Assertion: Transition metals show their highest oxidation state with oxygen. Reason (R): The ability of oxygen to form multiple bonds to metals.2023 · asked 2×
- Which of the following transition metals shows +1 and +2 oxidation states?2026 · asked 2×
- Assertion: Actinoids show wide range of oxidation states. Reason (R): Actinoids are radioactive in nature.2025 · asked 2×
- With increase in atomic number, the melting point of transition metals:2025
- In which of the following does the central atom exhibit an oxidation state of+3?2023
- (i) Silver atom has completely filled d-orbitals in its ground state, it is still considered to be a transition element. Justify the statement. (ii)…2022
- Give reasons for the following statements: Copper does not displace hydrogen from acids. Transition metals and most of their compounds show…2022
- Which one among the following metals of 3d series has the lowest melting point?2023
CBSE Class 12 Chemistry past-paper question from the 2022 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.