(b) Why do \( \mathrm{NH}_{3}, \mathrm{H}_{2} \mathrm{O} \) and HF have higher boiling point than those of \( \mathrm{PH}_{3}, \mathrm{H}_{2} \mathrm{~S} \) and HBr ?
(c) account for the observation that although \( \mathrm{CO}_{2} \) and \( \mathrm{SO}_{2} \) have the same empirical formulae, CO 2 is non polar while \( \mathrm{SO}_{2} \) is polar.