`Co^(2+)(aq.)+SCN^(-)(aq.)to"Complex"(X)`
`Ni^(2+)(aq.)+"Dimethylglyoxime"overset(NH_4OH)to"Complex"(Y)`.
The coordination number of cobalt and nickel in complexes X and Y is four.
The IUPAC name of the complexes (X) and (Y) are respectively:

Options

A. (X) is paramagnetic with two unpaired electrons
B. (Y) is diamagnetic and shows intermolecular H-bonding
C. (X) is paramagnetic with three unpaired electrons and (Y) is diamagnetic
D. (X) and (Y) both are diamagnetic

Answer

C

Explanation

`(X)=[Co(SCN)_4]^(2-)`, cobalt in +2 oxidation state and `SCN^-` is weak field ligand.So,

`Y=[Ni(dmg)_2]`:Nickel is in +2 oxidation state and dmg is chelating ligand.So,

`[Ni(dmg)_2]` shows intra molecular H-bonding as shown below.
Reaction involved:
`Co^(2+)(aq)+4SCN^(-)(aq)to[Co(SCN)_4]^(2-)(aq.)` blue colour complex.