The phase diagram for sulfur is shown here. The rhombic and monoclinic states are two solid states with different structures. a. Below what pressure does solid sulfur sublime?

Key Concepts

Phase Diagram

A phase diagram is a graphical representation that shows the phases of a substance at various temperatures and pressures. It delineates the boundaries between different states of matter—solid, liquid, and gas—and indicates conditions under which these phases coexist. Understanding phase diagrams is crucial for predicting the behavior of substances under varying environmental conditions.

Sublimation

Sublimation is the process by which a solid transitions directly into a gas without passing through the liquid phase. This phenomenon occurs under specific temperature and pressure conditions, typically at low pressures for certain substances. In the context of sulfur, identifying the pressure below which sublimation occurs is essential for understanding its phase behavior.

Solid States of Sulfur

Sulfur can exist in different solid forms, primarily rhombic and monoclinic, each with distinct crystal structures and properties. The rhombic form is stable at room temperature and atmospheric pressure, while the monoclinic form is stable at higher temperatures. Recognizing these solid states is important for interpreting the phase diagram and understanding the conditions under which sublimation occurs.