Which molecule will undergo only London dispersion forces when interacting with other molecules of the same kind? Which molecule will undergo only London dispersion forces when interacting with other molecules of the same kind?

A. C4H10

B. NaC2H3O2

C. CH2Cl2

D. C2H5OH HF

A. C₄H₁₀

Explanation:

The intermolecular forces are the forces that bond together the molecules in a substance. The force depends on the polarity of the compound, which is related to the electronegativity of the elements and the dipole moment of the molecule.

When the elements have huge differences of electronegativities, the bond is polar, when they are similar, the bond is nonpolar. When the dipole moment on the molecule is 0, it's nonpolar, and when it is different from 0, it's polar.

At nonpolar molecules, the forces are weak, and partial charges must be induced so they can bond, at these molecules, the force is called London dispersion forces. At polar molecules, the polarity does partial charges, so the bond is stronger, and it's called dipole-dipole. If the hydrogen is bonded with a huge electronegative atom (F, O, or N), the dipole-dipole is even strong, and it's called hydrogen bond. At ionic compounds, the attraction force is called ionic force.

In letter a, the compound is nonpolar, so the intermolecular force is London dispersion force; in letter b, the compound is ionic (Na is a metal and the other part is covalent), so the force is ionic; in letter c, two compounds are possible, one is nonpolar, with London dispersion force, and the other is polar with dipole-dipole force; in letter d both have hydrogen bonds (H bonded to O, and H bonded to F).