ANSWERS OF Crystal Field Theory (CFT)

 

Here are the answers to the Crystal Field Theory (CFT) fill-in-the-blanks question paper:

Topic	Answers
1. Crystal Field Theory	According to Crystal Field Theory, the interaction between the ligands and the metal ion leads to splitting of d-orbitals in metal ions.
2. d-Orbital Splitting in Octahedral Field	In an octahedral crystal field, the d-orbitals split into two sets: t₂g and eg.
3. d-Orbital Splitting in Tetrahedral Field	In a tetrahedral crystal field, the d-orbitals split into two sets: eg and t₂g.
4. Energy Difference in Octahedral Field	The energy difference between the two sets of d-orbitals in an octahedral field is called crystal field splitting energy and is represented by Δ₀.
5. Strong Field Ligands	Ligands that cause greater splitting of d-orbitals are called strong field ligands and result in low spin complexes.
6. Weak Field Ligands	Ligands that cause lesser splitting of d-orbitals are called weak field ligands and usually lead to high spin complexes.
7. Splitting in Tetrahedral Complex	In tetrahedral complexes, the d-orbitals split in a reverse manner compared to octahedral complexes, with the eg set having higher energy.
8. High Spin Complex	A high spin complex occurs when the crystal field splitting energy (Δ) is small compared to the pairing energy, leading to more unpaired electrons.
9. Low Spin Complex	A low spin complex occurs when the crystal field splitting energy (Δ) is large compared to the pairing energy, causing maximum pairing of electrons.
10. Factors Affecting Splitting Energy	The magnitude of crystal field splitting (Δ) depends on the nature of the ligand and the oxidation state of the metal ion.
11. Color of Coordination Compounds	The color of coordination compounds is due to the d-d transitions between the split orbitals of the metal ion.
12. Crystal Field Stabilization Energy (CFSE)	The stability of a complex due to crystal field splitting is quantified by the Crystal Field Stabilization Energy (CFSE), represented as ΔCFSE.
13. Octahedral Complex Example	An example of an octahedral complex where d-orbitals split according to CFT is [Fe(CN)₆]³⁻.
14. Tetrahedral Complex Example	An example of a tetrahedral complex with reverse d-orbital splitting is [NiCl₄]²⁻.
15. Magnetic Properties of Complexes	Complexes with unpaired electrons are paramagnetic, while those with paired electrons are diamagnetic.

These answers will help solidify your understanding of Crystal Field Theory and its application to coordination compounds.