Dimethylglyoxime is a ligand having a capability to bind with metals.

Complete step by step solution: - In the question it is given that to find the incorrect statement regarding DMG among the given options.

Coming to given options, option A, It is tetradentate ligand.

It is incorrect because DMG is bidentate ligand means it can form two bonds with metal.

Means DMG has two donor atoms in it.

Coming to option B, Chelating agent.

It is true because DMG forms chelate or complex with metals when it reacts with them.

It is also correct because it contains diacetyl in its structure.

The structure of DMG is as follows.

Coming to option D, In gravimetric determination of Ni is used.

It is also correct because in gravimetric analysis to determine the amount of nickel, DMG is going to be used because it forms a complex with nickel.

Therefore DMG is not a tetradentate ligand.

Note: DMG forms complex or chelates with Nickel, Palladium, and cobalt metals.

DMG is less soluble in water but highly soluble in a solution of sodium hydroxide and methanol.

Dmg Palladium Nickel