Class 12th Chemistry 2017 Set1 Outside Delhi Board Paper Solution
(a) What type of isomerism shown by the complex
[Co(NH3)5 (SCN)]2+ ?
(b) Why is [NiCl4]2- paramegnatic while [Ni(CN)4]2- is diamagnetic?
(Atomic number of Ni = 28)
(c) Why are low spin tetrahedral complexes rarely observed?
(a) This complex is Linkage isomerism
(b) Because Ni[Cl4]2- has 2 unpaired electrons and is Paramagnetic. While Ni[CN4]2- has paired electrons and is Diamagnetic.
(c) There are only 4 ligands in a tetrahedral complex. So,the ligand field is roughly 2/3 of the octahedral field. The direction of DC ligand approach in tetrahedral complex does not coincide with the d-orbitals. This reduces the field by a factor of 2/3. Hence, ∆t is roughly 2/3 x 2/3 = 4/9 of ∆o.
As a result, all tetrahedral complexes are high-spin since the CFSE is normally smaller than the paring energy.
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(xiii) 2-Chloropropane to 1-propanol
(xiv) Isopropyl alcohol to iodoform
(xv) Chlorobenzene to p-nitrophenol
(xvi) 2-Bromopropane to 1-bromopropane
(xvii) Chloroethane to butane
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(xix) tert-Butyl bromide to isobutyl bromide
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