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8. Transition and inner transition element 12th chem CET MCQ

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[2013] 1. Which of the following ion is diamagnetic? (A) Sc 3+ (B) Ni 2+ (C) V 3+ (D) Fe 2+ Correct Answer: (A) Sc 3+ Solution: Sc (Z=21) has the configuration [Ar] 3d¹ 4s². In the +3 oxidation state, it loses 3 electrons to become [Ar] 3d⁰. Since there are no unpaired electrons, it is diamagnetic[cite: 10]. [2014] 2. Select the coloured compound amongst the following. (Atomic no. Ti=22, Cr=24 Cu=29, Zn=30) (A) TiCl 4 (B) CrCl 3 (C) ZnCl 2 (D) CuCl Correct Answer: (B) CrCl 3 Solution: Colour in transition metal compounds is due to d-d transitions[cite: 20]. Cr³⁺ (3d³) has unpaired electrons, making it coloured[cite: 30]. Ti⁴⁺ (3d⁰), Zn²⁺ (3d¹⁰), and Cu⁺ (3d¹⁰) do not have unpaired electrons in the d-subshell. ...
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9. Coordination compounds 12th Chem CET MCQs

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[2015] 1. [Cr(NH 3 ) 6 ][Cr(SCN) 6 ] and [Cr(NH 3 ) 2 (SCN) 4 ][Cr(NH 3 ) 4 (SCN) 2 ] are examples of what type of isomerism? (A) Ionisation isomerism (B) Linkage isomerism (C) Coordination isomerism (D) Solvate isomerism Correct Answer: (C) Coordination isomerism Solution: Coordination isomerism occurs when there is an interchange of ligands between the cationic and anionic coordination spheres of different metal ions. [2016] 2. Which of the following is a neutral complex? (A) [Pt(NH 3 ) 2 Cl 2 ] (B) [Co(NH 3 ) 6 ]Cl 3 (div) [Ni(NH 3 ) 6 ]Cl 2 (D) K 4 [Fe(CN) 6 ] Correct Answer: (A) [Pt(NH 3 ) 2 Cl 2 ] Solution: A neutral complex has no net charge. In [Pt(NH 3 ) 2 Cl 2 ], the +2 charge of Pt is balanced by two -1 charges of C...
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