Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory:
\((i) [Fe(CN)_6]^{4-} \)
\((ii) [FeF_6]^{3-}\)
\((iii) [Co(C_2O_4)_3]^{3-} \)
\((iv) [CoF_6]^{3-}\)
\((i) [Fe(CN)_6]^{4-} \)
\((ii) [FeF_6]^{3-}\)
\((iii) [Co(C_2O_4)_3]^{3-} \)
\((iv) [CoF_6]^{3-}\)
Solution and Explanation
\((i) [Fe(CN)_6]^{4-}\)
In the above coordination complex, iron exists in the +II oxidation state.
\(Fe^{ 2+}\) : Electronic configuration is \(3d ^{6} \)
Orbitals of \(Fe^{ 2+}\) ion:
Hence, the geometry of the complex is octahedral and the complex is diamagnetic (as there are no unpaired electrons).
\((ii) [FeF_6]^{ 3-} \)
In this complex, the oxidation state of Fe is +3.
Orbitals of \(Fe^{+3}\) ion: 
\((iii) [Co(C_2O_4)_3]^{ 3-}\)
Cobalt exists in the +3 oxidation state in the given complex
Orbitals of \(Co ^{3+}\) ion: 
\((iv) [CoF_6]^{ 3-}\)
Cobalt exists in the \(+3 \) oxidation state.
Orbitals of \(Co^{3+}\) ion: 
Top Questions on Coordination Compounds
- Assertion (A): [Cr(H$_2$O)$_6$]Cl$_2$ and [Fe(H$_2$O)$_6$]Cl$_2$ are examples of homoleptic complexes.
Reason (R): All the ligands attached to the metal are the same.- CBSE CLASS XII - 2025
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- On the basis of \(\Delta_0\) and P (pairing energy), how can you differentiate between a strong field ligand and a weak field ligand?
- CBSE CLASS XII - 2025
- Chemistry
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The Crystal Field Theory (CFT) of coordination compounds is based on the effect of different crystal fields (provided by the ligands taken as point charges) on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. In tetrahedral coordination entity formation, the d-orbital splitting is smaller as compared to the octahedral entity.
What is crystal field splitting energy?- CBSE CLASS XII - 2025
- Chemistry
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- Why are low spin tetrahedral complexes rarely observed?
- CBSE CLASS XII - 2025
- Chemistry
- Coordination Compounds
The Crystal Field Theory (CFT) of coordination compounds is based on the effect of different crystal fields (provided by the ligands taken as point charges) on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. In tetrahedral coordination entity formation, the d-orbital splitting is smaller as compared to the octahedral entity.
On the basis of CFT, explain why [Ti(H$_2$O)$_6$]Cl$_3$ complex is coloured? What happens on heating the complex [Ti(H$_2$O)$_6$]Cl$_3$? Give reason.- CBSE CLASS XII - 2025
- Chemistry
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Questions Asked in CBSE CLASS XII exam
- The firm of Amish, Nitish and Misha, who have been sharing profits in the ratio of 2 : 2 : 1, have existed for some years. Misha wanted that she should get equal share in the profits with Amish and Nitish and she further wished that the change in the profit sharing ratio should come into effect retrospectively for the last three years. Amish and Nitish had agreement for this.
The profits for the last three years were: 2021–22 ₹ 1,15,000; 2022–23 ₹ 1,24,000; 2023–24 ₹ 2,11,000
Show adjustment of profits by means of a single adjustment journal entry. Show your working clearly.- CBSE CLASS XII - 2025
- Profit sharing ratio
- List two reasons that make copper releasing IUDs as effective contraceptives.
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A carpenter needs to make a wooden cuboidal box, closed from all sides, which has a square base and fixed volume. Since he is short of the paint required to paint the box on completion, he wants the surface area to be minimum.
On the basis of the above information, answer the following questions :
Find \( \frac{dS}{dx} \).- CBSE CLASS XII - 2025
- Differentiation
- Zaina, Yash and Kiran were partners in a firm sharing profits and losses in the ratio of 2 : 2 : 1. Zaina died on 1st July, 2024. As per the partnership deed, Zaina’s share of profit or loss till the date of her death was to be calculated on the basis of sales. Sales for the year ended 31st March, 2024 amounted to ₹ 4,00,000 and that from 1st April to 30th June, 2024 was ₹ 1,50,000. The profit for the year ending 31st March, 2024 was ₹ 1,00,000. Calculate Zaina’s share of profit in the firm till the date of her death and pass necessary journal entry for the same.
- CBSE CLASS XII - 2025
- Retirement and Death of a Partner
- Alok, Sameer and Tushar were partners in a firm sharing profits and losses in the ratio of 4 : 3 : 2. With effect from 1st April, 2024, they decided to share future profits and losses in the ratio of 3 : 2 : 4. Their Balance Sheet as at 31st March, 2024 showed the following: (i) Advertisement Suspense Account \u20b9 90,000.
(ii) Credit Balance of \u20b9 2,70,000 in Profit and Loss Account.
Goodwill of the firm was valued at \u20b9 4,50,000 and revaluation of assets and liabilities resulted in a loss of \u20b9 1,80,000. Partners did not want to distribute the amount of Advertisement Suspense Account and the Profit and Loss Account. They also decided that revalued values of assets and liabilities were not to be recorded in the books. Pass a single adjustment entry to give effect to the above. Also show your workings clearly.- CBSE CLASS XII - 2025
- Admission of a Partner
Concepts Used:
Applications of Coordination Compounds
There are three applications of coordination compounds:
- Zinc-complex enzymes like carbonic anhydrase important to buffering reactions in blood.
- Copper-complex enzymes important to iron storage and producing pigments in hair, skin, and eyes.
- Nickel-complex enzymes as part of the enzymes urease and hydrogenase