Question

21 predict what type of van der waals interactions occur between molecules of o₂, scl₂, and ch₄ in liquids of these substances?

Explanation:

To determine the van der Waals interactions for each molecule:

• \( \boldsymbol{O_2} \): Diatomic, non - polar (same atoms, symmetric). Van der Waals force here is London dispersion forces (arise from temporary electron - cloud distortions, present in all molecules, dominant in non - polar ones).
• \( \boldsymbol{SCl_2} \): Polar molecule (S - Cl bonds are polar, and the molecular geometry is bent, so there is a net dipole moment). So, it has dipole - dipole interactions (between permanent dipoles) and also London dispersion forces (since all molecules have these, but dipole - dipole is the main additional force here).
• \( \boldsymbol{CH_4} \): Tetrahedral geometry, symmetric, non - polar (C - H bonds have very little polarity, and symmetry cancels any dipole). Thus, only London dispersion forces (temporary dipole - induced dipole interactions) act between its molecules.

Answer:

• For \( O_2 \): London dispersion forces.
• For \( SCl_2 \): Dipole - dipole interactions and London dispersion forces.
• For \( CH_4 \): London dispersion forces.