Question

The negative ligand is?
A) Aqua
B) Sulfato
C) Carboxyl
D) Nitrosonium

Answer 1

We must have to know that in a coordination complex, there are metal, coordination complexes and ligands attached to it. The metal, ligands and counter ion together forms a coordination complex. Positively charged species are cations, negatively charged species are anions and neutral species carry no charge.

Complete answer:
We must have to know that the ligands are the ions, atoms or molecules that donate lone pairs of electrons to the central metal ion in order to form coordination complexes. Ligand can be positive or negative or neutral also, that means it can be a cation, an anion or neutral species that carries no charge. We look at all the options to solve this question
Option A) this is an incorrect option since aqua ligand comes under the category of neutral ligand as it carries no charge on it. It can be represented as ${H_2}O$
Option B) This is a correct option as sulphato is a negative ligand which can be represented as $S{O_4}^{2 - }$, as this ion carries negative two charges on it thus it is considered to be a negative ligand.
Option C) this is an incorrect option as this type of ligand is not formed, its carboxylate not carbonyl ligand. Carboxylate is a negative ligand not carboxyl ligand thus this option is incorrect.
Option D) this is an incorrect option as nitrosonium is a positive ligand as it carries positive charge in it. It can be represented as $N{O^ + }$.

So,the correct answer is Option B.

Note:
We must have to remember that the ligands can be positive or negative or neutral also, that means it can be a cation, an anion or neutral species that carries no charge. It can be ions, atoms or molecules that donate lone pairs of electrons to the central metal ion in order to form coordination complexes.