Coordination Compounds - 1 - Free MCQ Practice Test with solutions, NEET

Ambidentate Ligand: Nitro

• An ambidentate ligand is a type of polydentate ligand that can bind to a central atom in multiple ways because it has two or more donor atoms, but uses only one of them in forming a coordinate bond at a time.
• Nitro (NO^2-) is an example of an ambidentate ligand. It can coordinate to the central metal atom either through the nitrogen atom (forming a nitro complex) or through one of the oxygen atoms (forming a nitrito complex).
• The other options provided do not have this property. Oxalate is a bidentate ligand, meaning it simultaneously uses both of its oxygen atoms to bind to the central atom. Carbonyl is a monodentate ligand, it can only bind through the carbon atom of the C=O group. Acetate is also a monodentate ligand, it can only bind through the oxygen atom of the C=O group.

Therefore, among the given options, only Nitro is an ambidentate ligand.

Explanation of Chelating Ligand
A chelating ligand is a molecule that forms multiple bonds with a single metal ion. In other words, it can bind to a metal ion at more than one point, creating a ring-like structure. This process is known as chelation. Chelating ligands have two or more donor atoms, which allow them to form multiple bonds with a single metal ion. These ligands are used in various fields such as medicine, chemistry, and environmental science due to their ability to sequester metal ions.

Examination of Options
A: Cl^- Chloride ion (Cl-) is a monodentate ligand, meaning it can bind to a metal ion at only one point. Therefore, it is not a chelating ligand.
B: DMG DMG, or Dimethylglyoxime, is a type of ligand that can bind to a metal ion at two points, forming a five-membered ring. Thus, DMG is a chelating ligand.

C: H₂O Water (H₂O) is a monodentate ligand, meaning it can bind to a metal ion at only one point. Therefore, it is not a chelating ligand.
D: OH^- Hydroxide ion (OH^-) is a monodentate ligand, meaning it can bind to a metal ion at only one point. Therefore, it is not a chelating ligand.

Conclusion
Therefore, out of the given options, only DMG (Dimethylglyoxime) is a chelating ligand. Hence, the correct answer is B: DMG.

• The coordination number refers to the number of bonds formed between the central metal ion and surrounding ligands.
• In [Cr(NH3)3(H2O)3], chromium (Cr) is surrounded by three ammonia (NH3) molecules and three water (H2O) molecules.
• Each ligand forms one bond with the chromium ion, totaling six bonds.
• Thus, the coordination number of chromium in this complex is 6.

Since the reagent is BaCl₂(aq), displacement reaction will take place. The resulting solution, if insoluble in water, will form a white precipitate. Both BaNO₂ and BaCl₂ are soluble in water and hence will not form a precipitate. BaSO₄, however, is insoluble in water and hence forms a white precipitate.

Name of ligands name first in alphabetical order followed by anme of central ion.

oxidation state of Ag in tollen’s reagent is +1.

Multidentate ligands are capable of causing chelation because they have multiple binding sites. This allows them to form ring structures with the metal ion.

Therefore, option B is incorrect.

In option A, K₂NiF₆, each potassium ion has an oxidation state of +1, contributing a total of +2. Each fluorine ion has an oxidation state of -1, leading to a total of -6. To achieve electrical neutrality:

• The total positive charge from potassium is +2.
• The total negative charge from fluorine is -6.
• Nickel (Ni) must balance these charges.

This results in a +4 oxidation state for nickel. This is the highest oxidation state among all options provided.

KCl·MgCl₂·6H₂O is classified as a double salt because it contains two distinct salts:

• Potassium chloride (KCl)
• Magnesium chloride (MgCl₂)

These salts are present in a fixed molar ratio within the same crystal lattice. The key characteristics of this composition include:

• It does not form new ions or complexes.
• It aligns with the definition of a double salt rather than a mixed, basic, or complex salt.

In A one and more different types of ligands are present.

Oxalate (C₂O₄^2-) is a bidentate ligand, meaning it can form two bonds with a central metal ion. This ability allows it to create chelate complexes, which are complexes where a multidentate ligand forms a ring structure by binding to the metal through multiple donor atoms.

Among the given options, only oxalate (D) is capable of forming such chelate complexes.

Central Metal ion behave as a Lewis Acid while Ligand act as a lewis Base.

The cyclopentadienyl ligand, C₅H₅^-, is a negative ligand commonly used in organometallic chemistry. It is notably found in the compound ferrocene.

This makes option B the correct answer.

Ligands are named 1st followed by the name of central metal ion.

Cis Platin (cis – [Pt(NH₃)₂(Cl)₂] is a anti cancer drug.

This is double salt so name is written in sequential manner.

Sodium pentacyanonitrosylferrate(II) is chemically represented as Na₂[Fe(CN)₅NO]. This compound is commonly known as Sodium nitroprusside, which corresponds to option C.

The dsp² hybridization involves the use of:

• One d orbital
• One s orbital
• Two p orbitals

This results in four hybrid orbitals. This configuration leads to:

• A square planar geometry
• An arrangement of electron pairs and ligands around the central atom

This geometry is commonly observed in:

• Coordination compounds with strong field ligands
• Specific electronic configurations that favour this structure

Complex carbonyls follow Sidwick's EAN rule i.e compound with EAN 36 will be relatively more stable than other metal carbonyls. Iron pentacarbonyl has EAN number of 36 = Z−X+Y = (26−0+2x)
[Z = atomic number, X = oxidation state of metal, Y= total electrons donated by ligand]
∴x = 5. So, the formula will be Fe(CO)5.

Bis(acetylacetonato)oxovanadium(IV) has square pyramidal geometry.

[Ni(CO)₄] has tetrahedral geometry so hybridisation is sp³

Primary valency is equal to no. of ligands attachted which are negatively charges.

EAN = 28 (Z) – 2 (oxidation number) + 2*4 (CN) = 34

Hence A

The complex [PtCl₃(NH₃)₃]Cl has only one ionisable chlorine