Which of the following molecules would have the strongest London dispersion forces?

• A. CH4
• B. CO2
• C. CCl4
• D. NH3

Answer: (C)

Verified step by step guidance

1. Identify that London dispersion forces are a type of van der Waals force that arise due to temporary fluctuations in electron density, creating instantaneous dipoles even in nonpolar molecules.
2. Recognize that the strength of London dispersion forces generally increases with the number of electrons and the size (molar mass) of the molecule, because larger electron clouds are more easily polarizable.
3. Compare the molecular weights and sizes of the given molecules: CH4 (methane), CO2 (carbon dioxide), CCl4 (carbon tetrachloride), and NH3 (ammonia).
4. Note that CCl4 has the largest molar mass and the most electrons among the options, which leads to stronger London dispersion forces compared to the others.
5. Conclude that because London dispersion forces dominate in nonpolar molecules and increase with molecular size and electron count, CCl4 exhibits the strongest London dispersion forces among the given molecules.