Which of the following molecules would exhibit the strongest dipole-dipole interactions?

• A. CCl4
• B. CH4
• C. CH3Cl
• D. CO2

Answer: (C)

Verified step by step guidance

1. Identify the molecular geometry and polarity of each molecule listed: CCl4, CH4, CH3Cl, and CO2.
2. Recall that dipole-dipole interactions occur between polar molecules, so determine which molecules have a net dipole moment by analyzing their molecular shapes and the electronegativity differences between atoms.
3. For CCl4 and CO2, note that both are symmetrical molecules (tetrahedral for CCl4 and linear for CO2) with polar bonds that cancel out, resulting in nonpolar molecules with no net dipole moment.
4. For CH4, recognize that it is a nonpolar molecule because it is symmetrical with identical C-H bonds, so it has very weak or no dipole-dipole interactions.
5. For CH3Cl, observe that the molecule is asymmetrical due to the presence of the more electronegative chlorine atom replacing one hydrogen, creating a net dipole moment and thus the strongest dipole-dipole interactions among the options.