London Dispersion Forces Quiz

What is the primary cause of London dispersion forces?

Which statement best describes the strength of London dispersion forces compared to other intermolecular forces?

What term is sometimes used synonymously with London dispersion forces?

How does a temporary dipole form in a nonpolar molecule?

What is an 'induced' dipole in the context of London dispersion forces?

Which of the following is NOT an example of a substance that exhibits London dispersion forces as its primary intermolecular force?

What factor makes London Dispersion Forces significant in halogens such as Iodine (I2) and Bromine (Br2)

Which statement accurately describes how London Dispersion forces relate to the polarity of a molecule?

London Dispersion Forces

Named after Fritz London, a German-American physicist who first described these forces in 1930
Weak intermolecular forces present in all molecules, including nonpolar molecules
Caused by temporary fluctuations in electron distribution
These fluctuations create temporary dipoles, leading to attractive forces between molecules
The strength of the force increases with the size and electron count of the molecule
London dispersion forces are the weakest intermolecular force

Key Features

Temporary Dipoles: Electrons in an atom or molecule can become unevenly distributed, creating a temporary dipole
Induced Dipoles: A temporary dipole in one molecule can induce a dipole in a neighboring molecule, resulting in an attractive force
Attractive Force: The temporary dipoles in neighboring molecules create an electrostatic attraction between them

Examples

Noble Gases (He, Ne, Ar): These are nonpolar molecules, and the only intermolecular force they experience is London Dispersion Force.
Nonpolar Molecules (O2, CO2, CH4): These molecules are nonpolar, and also experience London Dispersion Forces
Halogens (I2, Br2): These are examples of molecules where dispersion forces are significant due to their large size and electron count, leading to stronger temporary dipoles

Summary

London Dispersion Forces are weak, but significant intermolecular forces
Present in all molecules, even nonpolar ones
These forces play a role in the properties of gases and liquids, especially for nonpolar substances

Test your knowledge on London dispersion forces, a key concept in understanding intermolecular interactions. This quiz covers the basics, including temporary and induced dipoles, and the significance of these weak forces in various molecules. Perfect for students of chemistry looking to reinforce their understanding!