Advertisements
Advertisements
Question
Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following:
\[\ce{[FeF6]^{3-}, [Fe(H2O)6]^{2+}, [Fe(CN)6]^{4-}}\]
Advertisements
Solution
(1) \[\ce{FeF^{3-}6}\]:
\[\ce{Fe^{3+} = 3d^5}\]
Number of unpaired electrons = 5
Magnetic moment = `sqrt(5(5 + 2))` = 5.92 BM
(2) \[\ce{[Fe(H2O)6]^{2+}}\]:
\[\ce{Fe^{2+} = 3d^6}\]
Number of unpaired electrons = 4
Magnetic moment = `sqrt(4(4 + 2))` = 4.9 BM
(3) \[\ce{[Fe(CN)6]^{4-}}\]:
\[\ce{Fe^{2+} = 3d^6}\]
Since CN– is a strong field ligand all the electrons get paired.
No unpaired electrons so diamagnetic.
APPEARS IN
RELATED QUESTIONS
On the basis of crystal field theory, write the electronic configuration for d4 ion if Δ0 > P.
The hexaquo manganese(II) ion contains five unpaired electrons, while the hexacyanoion contains only one unpaired electron. Explain using Crystal Field Theory.
State the superiority of crystal field theory over valence bond theory.
Write the electronic configuration of Fe(III) on the basis of crystal field theory when it forms an octahedral complex in the presence of (i) strong field, and (ii) weak field ligand. (Atomic no.of Fe=26)
Draw the structures of the following :
(1) XeF6
(2) IF7
The CFSE for octahedral \[\ce{[CoCl6]^{4-}}\] is 18,000 cm–1. The CFSE for tetrahedral \[\ce{[CoCl4]^{2-}}\] will be ______.
Arrange following complex ions in increasing order of crystal field splitting energy (∆O):
\[\ce{[Cr(Cl)6]^{3-}, [Cr(CN)6]^{3-}, [Cr(NH3)6]^{3+}}\].
\[\ce{CuSO4 . 5H2O}\] is blue in colour while \[\ce{CuSO4}\] is colourless. Why?
Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following:
\[\ce{[CoF6]^{3-}, [Co(H2O)6]^{2+}, [Co(Cn)6]^{3-}}\]
The CFSE for octahedral [CoCl6]−4 is 18,000 cm−1. What will be the CFSE for tetrahedral [CoCl3]−2?
[Ni(H2O)6]2+ (aq) is green in colour whereas [Ni(H2O)4 (en)]2+ (aq)is blue in colour, give reason in support of your answer.
Considering crystal field theory, strong-field ligands such as CN–:
Crystal field stabilising energy for high spind4 octahedral complex is:-
What is the difference between a weak field ligand and a strong field ligand?
What is crystal field splitting energy?
The correct order of intensity of colors of the compounds is ______.
Read the passage carefully and answer the questions that follow.
|
Crystal field splitting by various ligands Metal complexes show different colours due to d-d transitions. The complex absorbs light of specific wavelength to promote the electron from t2g to eg level. The colour of the complex is due to the transmitted light, which is complementary of the colour absorbed. The wave number of light absorbed by different complexes of Cr ion are given below:
|
Answer the following questions:
(a) Out of ligands "A", "B", "C" and "D", which ligand causes maximum crystal field splitting? Why?
OR
Which of the two, “A” or “D” will be a weak field ligand? Why?
(b) Which of the complexes will be violet in colour? [CrA6]3- or [CrB6]3+ and why?
(Given: If 560 - 570 nm of light is absorbed, the colour of the complex observed is violet.)
(c) If the ligands attached to Cr3+ ion in the complexes given in the table above are water, cyanide ion, chloride ion, and ammonia (not in this order).
Identify the ligand, write the formula and IUPAC name of the following:
- [CrA6]3-
- [CrC6]3+
