1. Slide 1 of 17 Chemistry 17.4

2. © Copyright Pearson Prentice Hall Slide 2 of 17 Changes of State Familiar weather events can remind you that water exists on Earth as a liquid, a solid, and a vapor. As water cycles through the atmosphere, the oceans, and Earth’s crust, it undergoes repeated changes of state. You will learn what conditions can control the state of a substance. 13.4

3. © Copyright Pearson Prentice Hall Changes of State > Slide 3 of 17 Sublimation When can sublimation occur? 13.4

4. Slide 4 of 17 © Copyright Pearson Prentice Hall > Changes of StateSublimation The change of a substance from a solid to a vapor without passing through the liquid state is called sublimation. Sublimation occurs in solids with vapor pressures that exceed atmospheric pressure at or near room temperature. 13.4

5. Slide 5 of 17 © Copyright Pearson Prentice Hall > Changes of State Sublimation When solid iodine is heated, the crystals sublime, going directly from the solid to the gaseous state. When the vapor cools, it goes directly from the gaseous to the solid state. 13.4

6. © Copyright Pearson Prentice Hall Changes of State > Slide 6 of 17 Sublimation Simulation 14 Predict the physical states present at different points on a phase diagram.

7. © Copyright Pearson Prentice Hall Changes of State > Slide 7 of 17 Phase Diagrams How are the conditions at which phases are in equilibrium represented on a phase diagram? 13.4

8. Slide 8 of 17 © Copyright Pearson Prentice Hall > Changes of State Phase Diagrams A phase diagram is a graph that gives the conditions of temperature and pressure at which a substance exists as solid, liquid, and gas (vapor). 13.4

9. © Copyright Pearson Prentice Hall Changes of State > Slide 9 of 17 Phase Diagrams The conditions of pressure and temperature at which two phases exist in equilibrium are indicated on a phase diagram by a line separating the phases. 13.4

10. Slide 10 of 17 © Copyright Pearson Prentice Hall > Changes of State Phase Diagrams 13.4

11. Slide 11 of 17 © Copyright Pearson Prentice Hall > Changes of State Phase Diagrams The triple point describes the only set of conditions at which all three phases can exist in equilibrium with one another. 13.4

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