Question

Which of the following molecules has a net dipole moment of zero?

a) Water (H2O)
b) Ammonia (NH3)
c) Carbon dioxide (CO2)
d) Hydrogen fluoride (HF)

Answer 1

Carbon dioxide (CO2) has a net dipole moment of zero because its linear molecular geometry leads to the cancellation of its bond dipole moments, resulting in a nonpolar molecule.

Step-by-step explanation:

The molecule among Water (H2O), Ammonia (NH3), Carbon dioxide (CO2), and Hydrogen fluoride (HF) that has a net dipole moment of zero is Carbon dioxide (CO2). The molecular geometry of CO2 is linear with two identical C-O bonds that are polar.

However, due to the 180° angle between them, the bond dipole moments are equal and opposite, thus canceling each other out. This leaves CO2 with no net dipole moment, making it a nonpolar molecule. In contrast, H2O, NH3, and HF all have geometries that do not allow for their bond dipole moments to completely cancel, resulting in molecules with a net dipole moment.