1. The phase of a substance depends upon two parameters: Temperature Pressure Gives the particles more energy to overcome attractive forces. Raises the vapor pressure. Restricts the motion of particles. Changes the level to which vapor pressure has to get. Phase Diagram: A graphical way to summarize the conditions under which the different states of matter are stable for a particular substance.

2. P (atm) T→T→ 1.0 Solid Liquid Gas Triple Point (-57°C, 5.1 atm) -78°C ↑ < -78°C Sublimation Critical Point (31°C, 73 atm) Critical Pressure Critical Temperature CO 2 Maximum Vapor Pressure

3. P (atm) T (°C) → 1.0 Solid Liquid Gas Triple Point (0.01°C, 0.00603atm) 0 ↑ Critical Point (374°C, 218 atm) 100 TEMP TIME→ (constant heating) Water 0°C 100°C ← q = m c  T  H fus ← q = m c  T HvHvHvHv supercritical fluid

4. A.P. Chem Pressure (atm) Temperature (°C) 1.0 0.1 125 (Not to Scale) 0-100100200300 Solid is denser than the liquid Substance does not normally sublime T m (normal melting point) = -7.2°C T b (normal boiling point) = 58.8°C Maximum V.P. is 125 atm at 300.°C Triple Pt. is 44 mm of Hg and -7.5°C Problem: Construct a phase diagram for and identify this naturally occurring, electrically nonconductive element. solid liquid gas Br 2