JEE Main 12 Jan 2019 Evening Question 5

Question: The magnetic moment of an octahedral homoleptic Mn(II) complex is 5.9 B.M. The suitable ligand for this complex is [JEE Main Online Paper Held On 12-Jan-2019 Evening]

Options:

A) $ NC{S^{-}} $

B) $ C{N^{-}} $

C) CO

D) ethylenediamine

Show Answer

Answer:

Correct Answer: A

Solution:

  • $ \mu =\sqrt{n(n+2)}=5.9B.M. $
    $ \Rightarrow n=5 $ (Where, n = no. of unpaired electrons]
    $ M{n^{2+}}=[Ar]3d^{5} $
    Five unpaired electrons in 3d-orbital are possible under influence of only weak field ligand. Among the given, $ NC{S^{-}} $ is relatively weak.