When diemethyl glyoxime is added to the aqueous solution of nickel (II) chloride in presence of dilute ammonia solution, a bright red coloured precipitate is obtained .
(a) Draw the structure of bright red substance .
(b) Write the oxidation state of nickel in the substance and hybridisation.
(c ) State whether the substance is paramagnetic or diamagnetic.

Explanation

`Ni^(2+)+2dmg overset(NH_(4)OH)to[Ni(dmg)_(2)]darr"(bright red)"`
It acquires stability through chelation and intra molecular H-bonding.
In `[Ni(dmg)_(2)]` the nickel is in +2 oxidation state and to have square planar geometry because of chelation the pairing of electrons take place. So

As all electrons are paired, so complex is diamagnetic. Nickel with coordination number four will have the structure as given below.