Exams › JEE Advanced › Chemistry
Ni²+ forms complexes with coordination number 4. Given the reactions: NiCl2 + excess KCN -> Complex A NiCl2 + excess KCl -> Complex B What are the hybridisations of the central metal in A and B respectively?
- dsp2, sp3
- sp3, sp3
- dsp2, dsp2
- sp3d2, d2sp3
Correct answer: dsp2, sp3
Solution
CN⁻ is a strong-field ligand that forces pairing of the d⁸ electrons in Ni²+, vacating one d orbital, leading to dsp2 square planar geometry for complex A. Cl⁻ is a weak-field ligand that does not cause pairing, so complex B adopts sp3 tetrahedral geometry.
Related JEE Advanced Chemistry questions
- The pair(s) of coordination complexes/ions exhibiting the same kind of isomerism is(are) -
- A 0.01 molal solution of a cobalt(III) chloride-ammonia complex, which dissociates completely, has a freezing point of -0.0558°C. Based on this data, how many chloride ions are present within the coordination sphere of the complex? [Kf for water = 1.86 K kg mol⁻¹]
- What are the molecular shapes of the ammonia complexes formed by Ni²⁺, Pt²⁺, and Zn²⁺, respectively?
- What are the spin-only magnetic moments (in Bohr Magneton) for the complexes [Cr(NH₃)₆]³⁺ and [CuF₆]³⁻, given that the atomic numbers of Cr and Cu are 24 and 29, respectively?
- When K3[Fe(CN)6] reacts with freshly prepared FeSO4, a dark blue solid known as Turnbull's blue is formed. On the other hand, when K4[Fe(CN)6] reacts with FeSO4 in the complete absence of air, a white solid X is produced, which later turns blue when exposed to air. Additionally, if FeSO4 is mixed with NaNO3 and concentrated H2SO4 is carefully added along the side of a test tube, a brown ring forms. What is the chemical identity of precipitate X?
- Which of the following compounds is responsible for the appearance of the brown ring?
⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →