Difference Between Inductive Effect and Resonance Effect for JEE Main 2024

The inductive effect is the effect caused by the electric charges induced in the atoms of a molecule.This charge induction is caused by atoms with different electronegativity values. Atoms with high electronegativity tend to attract bonding electrons. However, the resonance effect is different from the inductive effect. The resonance effect of a molecule occurs when there are double bonds in that molecule.

The key difference between inductive and resonance effects is that inductive effects are caused by polarization of chemical bonds, whereas resonance effects are caused by the presence of single and double bonds together.

Atoms are associated with the terms inductive effect and resonance effect. The inductive effect is caused by the induced electrical charges in a molecule's atoms. The resonance effect, on the other hand, occurs when single bonds and double bonds alternate in a molecule.

What is the Inductive Effect?

The inductive effect is the effect caused by the transfer of electric charge through a chain of atoms. This charge transfer eventually leads to a permanent electrical charge on the atoms. The inductive effect arises because of the differences in the electronegative values ​​of the atoms in the molecule.

• The inductive effect arises from the transfer of electric charge through a chain of atoms. Ultimately, this transfer results in a permanent electrical charge on the atoms of the molecule. This effect also occurs when the electronegativity of atoms in the same molecule differ from each other.

• In general, atoms with high electronegativity values ​​tend to attract bonding electrons compared to atoms with low electronegativity values. So when two atoms in a covalent bond have a large difference in their electronegativity values, this results in the atom with the low electronegativity acquiring a partial positive electric charge.The second atom, on the other hand, acquires a negative charge, resulting in polarization of the bond. 

• And the whole process leads to an inductive effect. Also, there are two types of effects; These are the electron withdrawing effect and the electron donating effect.Furthermore, this inductive effect has a direct influence on the stability of the molecules. Therefore, it is particularly important in organic molecules.For example, if a carbon atom in an organic molecule has a partial positive charge, electron donating groups such as an alkyl group can donate or share their electrons to that carbon atom, thereby reducing the positive charge on that carbon atom. This increases the stability of the organic molecule.

There are two ways to find the inductive effect.

i) Electron Withdrawing Inductive Effect

• Occurs when an atom or electronegative group becomes attached to a molecule. This atom or group attracts electrons from the rest of the molecule.

• The Inductive effect in a molecule is a local change in electron density caused by groups elsewhere in the molecule withdrawing or donating electrons, resulting in a permanent dipole in the bond. It occurs in σ-bonding (sigma), in contrast to the electromeric effect, which occurs in π-bonding (pi).Halogen atoms in an alkyl halide accept electrons, while alkyl groups tend to donate electrons.

• Then when an electronegative atom (without an electron and therefore with a positive charge) is connected to a chain of atoms, usually carbon, the positive charge is transferred to the other atoms in the chain. This is the inductive electron-withdrawing effect, also known as the -I effect.In short, alkyl groups tend to donate electrons, leading to the +I effect. Their experimental basis is the ionization constant. It differs from the mesomeric effect and often counteracts it.

ii) Electron Releasing Inductive Effect

This effect is observed when groups such as alkyl groups are attached to a molecule. These groups are less electron attractive and tend to donate electrons to the rest of the molecule.

The inductive effect has a direct impact on the stability of molecules, especially organic molecules. If the carbon atom has a partially positive charge, an electron donating group, such as an alkyl group, can reduce or remove those partially positively charged donor electrons. This increases the stability of this molecule.

What is the Resonance Effect?

The resonance effect describes the effect of a pi bond's electron interaction on the stability of a molecule. Lone pairs of electrons can also contribute to a molecule's resonance if the molecule's atoms have lone pairs of electrons. The resonance effect causes electrons to delocalize between atoms. The resonance is carried out by molecules with double bonds.We can use resonance structures to determine the actual structure of a molecule. The molecule's structure is an intermediate structure obtained through resonance stabilization. There are no isomers of the original molecule in resonance structures.

• If a molecule has only one resonance structure, that structure is the most stable in which the molecule can exist. Resonance structures are represented by Lewis structures.We can find the most stable intermediate structure for a molecule by listing all of its possible structures. 

• The resonance effect is the effect of single and double bonds on the stability of molecules. A double bond is the closest thing to a sigma bond. The resonance effect is caused by electron delocalization in pi bonds. Not only pi electrons, but also lone pairs of electrons, can contribute.

• Resonance occurs in molecules with alternating double bonds, and we can use resonance structures to accurately determine the chemical composition of a given molecule.Because the molecule is stabilized by resonance stabilization, its actual structure differs from that of a molecule with alternating double bonds.

Differentiate Between Inductive Effect and Resonance Effect

Conclusion

The resonance effect is a chemical phenomenon that occurs in organic molecules with double bonds. Organic molecules have double bonds in their structure and the p orbitals on opposite sides of the carbon atoms usually overlap. The polarity created in a molecule by the interaction between a lone pair of electrons and a pi bond is described by the resonance effect.This can also occur when two pi bonds of adjacent atoms come into contact. The inductive effect is a chemical term for the transfer of an unequal electron bond in a chain of atoms in a molecule, resulting in a permanent dipole in the bond.In contrast to the electromeric effect observed for (pi) bonding, it occurs for (sigma) bonding. Alkyl halides have halogen atoms that withdraw electrons, while alkyl groups tend to donate electrons. A positive charge is imparted to the other atoms in the chain when an electronegative atom (without an electron and therefore positively charged) is attached to a chain of atoms, usually carbon.