Question

Which one of the following is not a consequence of hybridisation? (1) effective overlapping of orbitals (2) minimised repulsion between orbital electrons (3) stronger bonds (4) enhanced reactivity of the molecule

Short answer

Option (4) is not a consequence of hybridisation.

Step-by-step solution

Understanding Hybridization

Hybridization is the process of combining atomic orbitals to form new hybrid orbitals. These hybrid orbitals lead to the effective overlapping of orbitals, minimization of repulsion between bonded electrons, and overall stronger bonds.

Evaluating Each Option

Examine each option to determine if it is a consequence of hybridization: 1) Effective overlapping of orbitals is a consequence. 2) Minimised repulsion between orbital electrons is a consequence. 3) Stronger bonds are a consequence. 4) Enhanced reactivity of the molecule is typically not a direct consequence of hybridization.

Identifying the Correct Option

From the evaluation, option (4) 'enhanced reactivity of the molecule' does not align directly with the primary consequences of hybridization.

Key concepts

Atomic Orbitals

In chemistry, atoms have regions around them known as atomic orbitals. These orbitals describe the spaces where electrons are likely to be found. Atomic orbitals come in different shapes—such as s, p, d, and f orbitals—each with varying energy levels.
When atoms come close to each other to form molecules, these atomic orbitals overlap and combine. This combination of orbitals is essential in the formation of chemical bonds, which hold the atoms together in molecules.
The arrangement of these orbitals around the nucleus and their interaction during molecule formation is critical in understanding how different atoms bond and react.

Effective Overlapping

Effective overlapping occurs when atomic orbitals combine to form a significant shared region of electron density between atoms. This is a crucial aspect of hybridization, which leads to the formation of stronger bonds.
For overlapping to be effective:

• The atomic orbitals must align properly.
• The phases of the overlapping orbitals should match.
• The energy levels of the orbitals should be close.

Effective overlapping results in the creation of hybrid orbitals, which exhibit enhanced bonding characteristics. It is one of the primary results of hybridization—helping form more stable and stronger bonds between atoms.

Bond Strength

Bond strength refers to how strongly two atoms are held together in a molecule. One of the factors influenced by hybridization is the bond strength between atoms. Hybridization increases the bond strength by ensuring effective overlapping of the atomic orbitals.
Here's why:

• Hybrid orbitals have more directional character, leading to better overlap.
• They combine orbitals with closer energy levels, which results in stronger and more stable bonds.
• They minimize electron repulsion, allowing for a more stable bond arrangement.

In essence, hybridization provides stronger bonds, contributing significantly to molecular stability.

Repulsion Between Electrons

In molecules, electrons can repel each other due to their negative charges. This repulsion can affect the shape and stability of molecules. Hybridization plays a role in minimizing these repulsions.
Here’s how hybridization helps:

• Hybrid orbitals spread out electrons more evenly around the atom.
• It enables more effective overlapping, which positions electrons in a more favorable arrangement.
• By combining orbitals that accommodate specific geometries, hybrid orbitals reduce the electron-electron repulsions.

The minimized repulsion between electrons in hybridized orbitals leads to more stable and less reactive molecules, hence better structural configurations.