Based on detailed analysis of last 5 years' papers. Perfect for 2026 Boards prep!
| Question Example | Type/Marks | Years Repeated | Notes |
|---|---|---|---|
| For [Co(NH₃)₆]³⁺: Hybridization, geometry, magnetic nature (diamagnetic, low spin). Compare with [CoF₆]³⁻ (paramagnetic, high spin). | Short Answer (2-3 marks) | 2021 Term 2, 2022, 2023, 2024, 2025 | Repeated 5x; d²sp³ octahedral, 0 unpaired vs sp³d², 4 unpaired. |
| Write IUPAC name for [Co(en)₂Cl₂]⁺. Explain geometrical isomerism (cis-trans). | Nomenclature/Reasoning (2 marks) | 2022, 2023, 2024, 2025 | Repeated 4x; Dichloridobis(ethane-1,2-diamine)cobalt(III). |
| Explain CFT for octahedral complexes. Draw splitting diagram, why ∆o > ∆t for tetrahedral? | Reasoning/Diagram (3 marks) | 2021 Term 1, 2022, 2023, 2025 | Repeated 4x; eg/t2g split vs t2/e. |
| Why are coordination compounds colored? Explain d-d transition in [Ti(H₂O)₆]³⁺ (d¹). | Short Answer (2 marks) | 2022, 2023, 2024, 2025 | Repeated 4x; Visible light absorption. |
| Assertion: [Ni(CN)₄]²⁻ is square planar and diamagnetic. Reason: Strong field CN⁻ causes pairing. | Assertion-Reason (1 mark) | 2023, 2024, 2025 | Repeated 3x; dsp², 0 unpaired. |
| Differentiate VBT and CFT. For [Fe(CN)₆]⁴⁻, hybridization and magnetic nature. | Comparison (3 marks) | 2021 Term 2, 2023, 2024 | Repeated 3x; VBT d²sp³, CFT low spin. |
| Explain linkage isomerism with example ([Co(NH₃)₅(NO₂)]²⁺ vs [Co(NH₃)₅(ONO)]²⁺). | Short Answer (2 marks) | 2022, 2024, 2025 | Repeated 3x; Nitro vs nitrito. |
| Biological importance: Haemoglobin (Fe²⁺ coordination), chlorophyll (Mg). | Case-Based (4 marks) | 2023, 2025 | Repeated 2x; O₂ binding. |
| MCQ: Optical isomers in [Co(en)₃]³⁺? (a) 2 (b) 0. | MCQ (1 mark) | 2024, 2025 | Repeated 2x; (a) d/l. |
| Spectrochemical series: Arrange ligands for [Co³⁺] complex (Cl⁻, NH₃, CN⁻) by field strength. | Short Answer (2 marks) | 2022, 2023 | Repeated 2x; Cl⁻ < NH₃ < CN⁻. |
Share this with your study group for 2026 Boards success!