Question

question 4 (1 point)
for a molecule to exhibit dipole - dipole interactions, it must...
a) have three or more atoms.
b) have a hydrogen bound to an oxygen, nitrogen, or fluorine.
c) have a permanent dipole moment.
d) be an ion.
e) have a temporary dipole moment.

Explanation:

Dipole - dipole interactions occur between polar molecules. A polar molecule has a permanent dipole moment due to the unequal sharing of electrons between atoms with different electronegativities.

• Option a: Molecules with two atoms (e.g., HCl) can also have dipole - dipole interactions if they are polar. So, having three or more atoms is not a requirement.
• Option b: Having a hydrogen bound to O, N, or F is a requirement for hydrogen bonding, not for general dipole - dipole interactions.
• Option c: A permanent dipole moment is necessary for dipole - dipole interactions. Polar molecules (with permanent dipoles) attract each other through these interactions.
• Option d: Ions are involved in ion - dipole or ion - ion interactions, not dipole - dipole interactions (which are between neutral polar molecules).
• Option e: Temporary dipole moments are associated with London dispersion forces (van der Waals forces), not dipole - dipole interactions.

Answer:

C. have a permanent dipole moment.