Intermolecular forces in PVC polymers

Steps:

• Identify PVC as a non-polar polymer made of repeating vinyl chloride units.
• Recognize that within each chain, atoms are linked by strong covalent bonds.
• Note that between separate polymer strands in solid PVC, only weak attractions hold them together.
• Determine the type of weak force: van der Waals, as PVC lacks polar groups for stronger bonds.

Why D is correct:

• Van der Waals forces are weak London dispersion attractions between non-polar polymer chains, allowing PVC to form a solid via intermolecular cohesion (defined as temporary dipole interactions).

Why the others are wrong:

• A. Covalent bonds form the backbone within each polymer strand, not between strands.
• B. Hydrogen bonds require electronegative atoms like N, O, or F with attached H; PVC (C-H, C-Cl) lacks these.
• C. Ionic bonds occur between charged ions; PVC is a covalent organic polymer without ions.

Final answer: D