Question

a. What is meant by an induced dipole? b. What is the everyday importance of this type of intermolecular force?

Short answer

An induced dipole is a temporary charge separation in a non-polar molecule. It's important for phenomena like gas condensation and material properties.

Step-by-step solution

- Define Induced Dipole

An induced dipole occurs when a non-polar molecule is momentarily polarized due to the presence of a nearby polar molecule or ion. This results in a temporary separation of charges within the non-polar molecule.

- Explain How Induced Dipoles Form

Induced dipoles form because the electron cloud of the non-polar molecule becomes distorted in the presence of a polar molecule or ion. This distortion leads to an uneven distribution of electrons, creating a temporary dipole moment.

- Everyday Importance of Induced Dipoles

Induced dipoles are important in everyday life because they are responsible for various physical behaviors, such as the condensation of gases into liquids and the solubility of gases in liquids. These forces also contribute to the properties of materials like plastics and rubbers, making them flexible and durable.

Key concepts

intermolecular forces

Intermolecular forces are the forces that act between molecules. They control many physical properties such as boiling points, melting points, and solubility.
While strong covalent or ionic bonds hold atoms together within a molecule, intermolecular forces determine how molecules interact with each other.
There are several types of intermolecular forces, including; dispersion forces (London forces), dipole-dipole interactions, and hydrogen bonds.
Induced dipole forces, also known as London dispersion forces, are one of the key types and occur even in non-polar molecules.

polar and non-polar molecules

Molecules can be either polar or non-polar. This distinction depends on the distribution of electrical charges.
Polar molecules have an uneven distribution of electrons, which leads to regions of partial positive and partial negative charges within the same molecule.
Examples include water (H₂O), where the oxygen atom is more negative and the hydrogen atoms are more positive.
Non-polar molecules have an even distribution of electrons, meaning no distinct positive or negative areas. Examples include gases like oxygen (O₂) and nitrogen (N₂).
Even though non-polar molecules tend to have no permanent dipole moment, they can still interact through induced dipoles.

temporary dipole moment

A temporary dipole moment occurs when non-polar molecules become polarized for a short period.
This happens due to the movement of electrons within the molecule or due to the presence of a nearby polar molecule or ion.
The temporary dipole induces a similar dipole in neighboring molecules, causing them to attract each other.
This is crucial for the condensation of gases and the solubility of gases in liquids.
While these dipole moments are fleeting, they are still strong enough to contribute significantly to intermolecular forces.

condensation of gases

Condensation refers to the process of gas turning into a liquid.
This occurs when gas molecules lose energy and come closer together, forming intermolecular attractions.
Induced dipole forces are responsible for this behavior, even in non-polar substances like nitrogen or oxygen.
As these gas molecules approach each other, temporary dipoles are formed, leading to the attraction and eventual condensation into a liquid.
This principle is crucial in everyday phenomena such as the formation of dew and the liquefaction of natural gases for storage and transport.

material properties

The physical properties of materials are influenced by intermolecular forces.
For example, plastics and rubbers are flexible and durable because of the induced dipole interactions between their polymer chains.
These forces allow the long chains to slide over each other while still being attracted, providing both flexibility and strength.
Additionally, the solubility of substances in different solvents depends on the types of intermolecular forces involved.
Thus, understanding induced dipoles helps in designing better materials with desired properties.