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प्रश्न
An aqueous pink solution of cobalt (II) chloride changes to deep blue on addition of excess of HCl. This is because:
(i) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl6]}^{4-}\]
(ii) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl4]}^{2-}\]
(iii) tetrahedral complexes have smaller crystal field splitting than octahedral complexes.
(iv) tetrahedral complexes have larger crystal field splitting than octahedral complex.
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उत्तर
(ii) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl4]}^{2-}\]
(iii) tetrahedral complexes have smaller crystal field splitting than octahedral complexes.
Explanation:
Aqueous pink solution of cobalt (II) chloride is due to electronic transition of electron from t2g to eg energy level of \[\ce{[Co(H2O)6]^{2+}}\] complex. When excess of HCl is added to this solution
(i) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl4]^{2-}}\].
(ii) Tetrahedral complexes have smaller crystal field splitting than octahedral complexes because Δr = `4/9` Δ0
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संबंधित प्रश्न
On the basis of crystal field theory, write the electronic configuration for d4 ion if Δ0 > P.
How are the following conversions carried out?
Benzoic acid into metanitrobenzoic acid.
Why are low spin tetrahedral complexes rarely observed?
Atomic number of \[\ce{Mn}\], \[\ce{Fe}\] and \[\ce{Co}\] are 25, 26 and 27 respectively. Which of the following inner orbital octahedral complex ions are diamagnetic?
(i) \[\ce{[Co(NH3)6]^{3+}}\]
(ii) \[\ce{[Mn(CN)6]^{3-}}\]
(iii) \[\ce{[Fe(CN)6]^{4-}}\]
(iv) \[\ce{[Fe(CN)6]^{3-}}\]
Atomic number of \[\ce{Mn, Fe, Co}\] and Ni are 25, 26, 27 and 28 respectively. Which of the following outer orbital octahedral complexes have same number of unpaired electrons?
(i) \[\ce{[MnCl6]^{3-}}\]
(ii) \[\ce{[FeF6]^{3-}}\]
(iii) \[\ce{[CoF6]^{3-}}\]
(iv) \[\ce{[Ni(NH3)6]^{2+}}\]
On the basis of crystal field theory explain why Co(III) forms paramagnetic octahedral complex with weak field ligands whereas it forms diamagnetic octahedral complex with strong field ligands.
Why are low spin tetrahedral complexes not formed?
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:
\[\ce{[CoF6]^{3-}, [Co(H2O)6]^{2+}, [Co(Cn)6]^{3-}}\]
[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.
The correct order of increasing crystal field strength in following series:
Crystal field stabilising energy for high spind4 octahedral complex is:-
The magnitude of CFSE depends upon ______
The CFSE of [CoCl6]3– is 18000 cm–1 the CFSE for [CoCl4]– will be ______.
Using crystal field theory, write the electronic configuration of d5 ion, if Δ0 > P.
What is the spectrochemical series?
For octahedral Mn(II) and tetrahedral Ni(II) complexes, consider the following statements:
- Both the complexes can be high spin.
- Ni(II) complex can very rarely below spin.
- With strong field Ligands, Mn(II) complexes can be low spin.
- Aqueous solution of Mn (II) ions is yellow in colour.
The correct statements are:
Read the passage carefully and answer the questions that follow.
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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:
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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+
The value of the spin only magnetic moment for one of the following configurations is 2.84 BM. The correct one is:
