Chapter 15, Problem 15.18P

Interpretation Introduction

Interpretation:

Molecules among ${\text{PH}}_3$, ${\text{NH}}_{\text{3}}$, $\text{KCl}$ and $\text{MgO}$ has to be arranged in the order of their increasing boiling points.

Concept Introduction:

Boiling point is temperature at which a liquid changes its state to vapor. Higher the force of attraction that holds the molecules, higher will be the boiling point.

Boiling point generally increases with increase in molecular mass. With increase in molecular mass, London forces between molecules also increase that is the main reason for the increase in boiling point. Presence of dipole-dipole interaction or hydrogen bond increases boiling point.