Final answer:
The substance that will NOT generate dipole-dipole interactions is D. O_2, as it is a nonpolar molecule with no permanent dipole, unlike the other substances listed.
Step-by-step explanation:
To determine which of the given substances does NOT generate dipole-dipole interactions, we need to identify the nonpolar molecule among the options A. HCl, B. CO, C. LiBr, and D. O2. Dipole-dipole interactions occur between polar molecules, which have a partial positive charge on one end and a partial negative charge on the other, resulting in a permanent dipole.
HCl (Option A) is a polar molecule as it has an H atom bonded to a Cl atom, which is more electronegative, leading to a dipole. CO (Option B) has a partial positive charge on the carbon and a partial negative charge on the oxygen, again resulting in a polar molecule with dipole-dipole interactions.
LiBr (Option C) is an ionic compound and therefore its dominant intermolecular forces are ionic, not dipole-dipole. Lastly, O2 (Option D) is a diatomic molecule with two identical atoms, which means there's no difference in electronegativity and thus no permanent dipole; it is nonpolar.
The substance that will NOT generate dipole-dipole interactions here is D. O2 because it is a nonpolar molecule with no permanent dipole.