Question

The clectron displacement cffect in which fractional polarization occurs duc to difference in electronegativitics is (1) Mesomeric cffect (2) Inductive effect (3) Monomeric effect (4) Inductomeric cffect

Short answer

Inductive effect

Step-by-step solution

- Understanding the Topic

Familiarize yourself with the concept of electron displacement and polarization in molecules based on differences in electronegativity.

- Review of Effects

Recall the definitions of the different effects listed: Mesomeric effect, Inductive effect, Monomeric effect, and Inductomeric effect.

- Mesomeric Effect

The mesomeric effect involves the delocalization of electrons in a molecule and is associated with resonance structures, not electronegativity differences.

- Inductive Effect

The inductive effect refers to the electron displacement through sigma bonds due to differences in electronegativity between atoms, leading to fractional polarization.

- Monomeric Effect

The monomeric effect is not a standard term in the context of electron displacement due to differences in electronegativity.

- Inductomeric Effect

The inductomeric effect is a combination of inductive and mesomeric effects, but fractional polarization due to electronegativity is primarily described by the inductive effect.

- Conclusion

Based on the analysis, the electron displacement effect causing fractional polarization due to electronegativity differences is described by the inductive effect.

Key concepts

Inductive Effect

The inductive effect refers to the shifting of electrons in a molecule through sigma bonds. This occurs due to differences in electronegativity between atoms bonded together. Electronegativity is an atom's ability to attract and hold onto electrons. When atoms with different electronegativities are bonded, electrons tend to move towards the more electronegative atom.
This causes a separation of charge, leading to fractional polarization of the bond. This effect is crucial in understanding the behavior of molecules, especially in organic chemistry.
Some key points about the inductive effect include:

• It is a permanent effect due to the nature of sigma bonds.
• It decreases with increasing distance from the electronegative atom.
• It can influence the reactivity and stability of molecules.

The inductive effect is commonly observed in halogen compounds, where the halogen atoms are more electronegative than carbon, drawing electron density towards themselves.

Polarization

Polarization describes the distribution of electrical charge over the atoms in a molecule. It is an important concept to grasp because it affects how molecules interact with each other and with electric fields.
Polarization occurs due to differences in electronegativity between atoms within a molecule. When one atom is more electronegative than another, it pulls electron density towards itself, leading to a dipole moment. This creates a slight separation of positive and negative charges.
There are two main types of polarization:

• Electronic Polarization: This occurs when an external electric field distorts the electron cloud of a molecule.
• Orientational Polarization: This happens when polar molecules align themselves in response to an external electric field.

Understanding polarization helps in predicting the physical and chemical properties of substances, such as solubility, boiling points, and interactions in different media.

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons. It plays a critical role in determining how electrons are distributed in a molecule.
The concept was first introduced by Linus Pauling, who assigned the first electronegativity values. The trends in electronegativity can be observed across the periodic table:

• Electronegativity increases from left to right across a period.
• Electronegativity decreases from top to bottom within a group.

Atoms with higher electronegativity tend to attract electrons more strongly, affecting the bond character.
For example, in a molecule like HCl, chlorine is more electronegative than hydrogen, resulting in a polar bond where electrons are more closely associated with the chlorine atom.
Understanding electronegativity is fundamental for predicting molecular behavior and bonding characteristics in chemistry.