Section 1
Why Does Matter Exist in Different Phases?
Draw a picture showing how $\mathrm{H}-\mathrm{Cl}$ molecules are attracted to one another, using dotted lines to represent intermolecular forces. Answer:
Based on the strength of their molecular dipole moments, which compound should have the higher boiling point, HF or HBr? Explain.
Draw a picture showing how $\mathrm{NH}_{3}$ molecules attract one another.
Based on the strength of their molecular dipole moments, which compound should have the higher boiling point, $\mathrm{H}_{2} \mathrm{~S}$ or $\mathrm{H}_{2} \mathrm{O}$ ? Explain.