Problem 34 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

The structure of which of the following chloro species can be explained on the basis of \(d s p^{2}\) hybridisation? (a) \(\mathrm{PdCl}_{4}^{2-}\) (b) \(\mathrm{FeCl}_{4}^{2-}\) (c) \(\mathrm{CoCl}_{4}^{2-}\) (d) \(\mathrm{NiCl}_{4}^{2-}\)

Step-by-Step Solution

Answer

The structure of \( \mathrm{PdCl}_{4}^{2-} \) can be explained by \( dsp^2 \) hybridisation.

Step 1: Understanding Hybridisation

To determine which species involves \( dsp^2 \) hybridisation, we need to identify the species that forms a square planar geometry. Square planar geometry typically involves \( dsp^2 \) hybridisation, as \( d \), \( s \), and two \( p \) orbitals mix to form four hybrid orbitals.

Step 2: Evaluating Each Option

Let's consider each complex: - \( \mathrm{PdCl}_{4}^{2-} \): Palladium typically forms square planar complexes, suggesting \( dsp^2 \) hybridisation.- \( \mathrm{FeCl}_{4}^{2-} \): Iron is more likely to form tetrahedral complexes with \( sp^3 \) hybridisation.- \( \mathrm{CoCl}_{4}^{2-} \): Cobalt in this oxidation state more commonly forms tetrahedral complexes with \( sp^3 \) hybridisation.- \( \mathrm{NiCl}_{4}^{2-} \): Nickel can form both square planar (\( dsp^2 \)) and tetrahedral (\( sp^3 \)) complexes, but in this anion, it typically adopts a \( sp^3 \) geometry.

Step 3: Selecting the Correct Option

The \( \mathrm{PdCl}_{4}^{2-} \) complex is known for its square planar configuration, which supports \( dsp^2 \) hybridisation. This makes it the correct answer since it aligns with our knowledge of its frequent electron configuration and geometry.

Key Concepts

dsp2 hybridisation

In chemistry, hybridisation is the process of mixing atomic orbitals to create new hybrid orbitals. This helps atoms form chemical bonds. The \( dsp^2 \) hybridisation is a specific type where one d orbital, one s orbital, and two p orbitals combine. This results in four four hybrid orbitals. These are arranged in a square planar geometry. This orientation is beneficial for minimizing electron repulsion in some complex compounds.

The \( dsp^2 \) hybridisation is particularly common in certain transition metal complexes. It occurs mostly with metals that lie in the second and third transition series.

• Palladium and Platinum frequently adopt this type of hybridisation. They often form square planar complexes due to the specific electron configuration of their d orbital.
• In the sulfide or chloride ions, these metal ions blend the orbitals to form stable bonds resulting in square planar complexes.

square planar complex

A square planar complex is a type of arrangement common in coordination chemistry. The central atom is placed at the center of a square, with four bonded atoms positioned at the corners. This setup arises usually due to \( dsp^2 \) hybridisation.

A few key characteristics of square planar complexes include:

• They typically involve transition metal ions with a coordination number of four.
• The famous example of a square planar complex is \( \mathrm{PdCl}_{4}^{2-} \), where the palladium ion is surrounded by four chlorine ions.
• Square planar complexes often display a flat shape which contrasts with the more common tetrahedral arrangements.

Unlike tetrahedral geometry that involves \( sp^3 \) hybridisation, square planar complexes are notable for how they utilize the \( dsp^2 \) hybridization. This allows for a unique spatial arrangement that leads to particular electronic and magnetic properties.

transition metal complexes

Transition metal complexes play a crucial role in many chemical processes and reactions. Transition metals are elements found in the d-block of the periodic table. They can form various complex substances with a wide range of properties.

These metals often exhibit interesting behaviors such as variable oxidation states and the ability to form colorful compounds. The presence of partially filled d orbitals in transition metals gives rise to distinct characteristics in their complexes.

Some fundamental aspects of transition metal complexes are:

• They have the ability to engage in different hybridisation like \( sp^3 \) or \( dsp^2 \), thus adopting diverse geometrical arrangements such as tetrahedral, square planar, or octahedral.
• The electronic and magnetic properties of these complexes depend on the metal's oxidation state and the nature of the ligands.
• The substitution of ligands in transition metal complexes can lead to varying stability and reactivity profiles.
• Useful in numerous applications including catalysis in industrial processes, they also form the basis for some biological systems like hemoglobin.

Understanding these complexes requires a grasp of their unique blends of electron configurations, bond formations, and geometrical structures.