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MDCAT/ECAT Quiz # 2 (Outer Transition Elements): InamJazbi Learn Chemistry 🚀
1. Zn²⁺ ion is colourless because:
Zn²⁺ has 3d¹⁰ (fully filled d-orbitals). No d–d transitions occur, so it is colourless.
2. The coordination number of cobalt in Na₄[Co(C₂O₄)₃] is:
Oxalate is bidentate. 3 ligands × 2 donor atoms = coordination number 6.
3. An example of a bidentate ligand is:
Oxalate binds through two donor oxygen atoms.
4. A highly paramagnetic ion among the following is:
Fe³⁺ has 5 unpaired electrons (maximum), so most paramagnetic.
5. The highest oxidation state of chromium is:
Cr has 6 valence electrons (3d⁵ 4s¹), max oxidation state = +6.
6. This element is NOT used for electroplating:
Mn forms rough oxides and is not used for smooth electroplating.
7. Steel typically used in making fry pans is:
Alloy steel is preferred for pans due to durability and heat resistance.
8. Step that removes gangue impurities in extraction of copper from chalcopyrite:
Concentration removes silica and earthy impurities.
9. 5d series of outer transition elements is:
La to Hg represents the 5d transition series.
10. Oxidation of manganese in air gives:
3Mn + 2O₂ → Mn₃O₄, a mixed oxidation state oxide.
11. The general valence shell electronic configuration of outer transition elements is:
General configuration: (n–1)d1-10, ns1-2 (n = 4–7) or (n–1)d1-10, ns0-2.
12. The general valence shell electronic configuration of inner transition elements is:
General configuration: (n–2)f1-14, (n–1)d0-1, ns0-1.
13. 4d series of outer transition elements is:
4d series: Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd (period 5 d-block).
14. The element with least atomic size in 3d series of outer transition elements is:
Nickel has the smallest atomic radius due to effective nuclear charge across the series.
15. The element with highest melting point in 3d series of outer transition elements is:
Cr (3d⁵4s¹) has max unpaired d-electrons → strongest metallic bonding → highest melting point.
16. The non-typical transition elements do not include:
Non-typical transition elements: Zn, Cd, Hg (d¹⁰, no variable oxidation states). Ag is less typical but included in transition properties.
17. The maximum oxidation state shown by elements in 3d series of outer transition elements is:
Mn (3d⁵4s²) → loses all 7 valence electrons → maximum oxidation state +7.
18. ………… catalysts are being explored for water splitting reactions:
Ru catalysts are explored for electrolysis to split water into H₂ and O₂.
19. Paramagnetic behaviour is the strongest for:
Mn²⁺ and Fe³⁺ → 5 unpaired electrons each → strongest paramagnetism.
20. Which one of the following is not paramagnetic?
Zn, Cd, Hg → completely filled d¹⁰ → diamagnetic → not paramagnetic.
21. Transition elements have the tendency to form alloys because of their similarities in:
Similar atomic sizes allow atoms to substitute each other in the crystal lattice → alloys form easily (e.g., brass, bronze, stainless steel).
22. Ferric ion (Fe³⁺) contains ………. unpaired electrons:
Fe³⁺ → [Ar] 3d⁵ → 5 unpaired electrons (half-filled d-orbital).
23. Colour in transition metal ions is associated with d-d transition of unpaired electrons from …………. set of energy levels:
Colour arises when electrons jump from lower t₂g orbitals to higher e g orbitals (d-d transitions). The absorbed wavelength corresponds to the energy gap Δ, producing complementary color.
24. The splitting of degenerate d-levels in the presence of ligand is known as:
Ligand approach causes electrostatic repulsion → d-orbitals split into t₂g and e g sets → called crystal field splitting.
25. The energy difference between t₂g and e g orbitals is commonly known as:
Energy difference between t₂g and e g orbitals is called Crystal Field Stabilization Energy (CFSE) and denoted ∆o (octahedral) or ∆t (tetrahedral).
26. Ti³⁺ complex absorbs yellow and green light while transmitting blue and red light, giving rise to the perception of:
Absorbed: yellow + green → transmitted complementary = violet → complex appears violet.
27. The ligand ‘en’ stands for:
"en" = Ethylene diamine (NH₂–CH₂–CH₂–NH₂), a bidentate ligand coordinating via two N atoms.
28. Three complexes are given below: (I) K₄[Fe(CN)₆], (II) [Cu(NH₃)₄]SO₄, (III) [Ni(CO)₄]. The ligands in these complexes are respectively:
Complex ligands: [Fe(CN)₆]⁴⁻ → CN⁻, [Cu(NH₃)₄]²⁺ → NH₃, [Ni(CO)₄] → CO.
29. The coordination ranges:
Known coordination numbers: 1–16; common range: 2–12 depending on metal size and ligands.
30. Which one of the following is paramagnetic?
Sc³⁺, Ti⁴⁺, V⁵⁺ → all d-orbitals empty → no unpaired electrons → diamagnetic → none are paramagnetic.