1. Phase Diagrams SOLID LIQUID GAS Critical Point Triple Point vaporizationcondensation sublimation deposition melting freezing

2. Critical point: Temperature and pressure beyond which it is impossible to condense the vapor into a liquid Triple point: Temperature and pressure at which all three phases coexist Normal boiling point: Temperature at which a liquid will boil under 1 atm of external pressure Normal freezing point: Temperature at which a liquid will freeze under 1 atm of external pressure What are the normal boiling and freezing points of water in  C? Normal BP: 100  C Normal FP: 0  C

3. Temperature (  C) Pressure (atm) 5.11 1.00 -78 Phase Diagram for Carbon Dioxide Why is it not possible to have liquid CO 2 at atmospheric pressure? Because CO 2 won’t condense at pressures below 5.11 atm.

4. 1.00 atm 0C0C 100  C Q: In terms of IMF’s, why is water’s phase diagram so different from the phase diagram for CO 2 ? CO 2 H2OH2O A: There is intermolecular hydrogen bonding present in water, but only LDFs in CO 2. Therefore, it takes more energy to separate water molecules from each other.

5. Temperature (°C) 0 100 Heating curve of water solid warming solid + liquid present liquid warming liquid + gas present Gas warming Heat (kJ/s)

6. Temperature (°C) 0 100 Heating curve of water melting/freezing point boiling/condensation point Temperature is constant during phase transitions!! All heat energy goes to changing the state of matter. Heat (kJ/s)

7. Heat (J) Temperature (  C) Heating Curve of Water vs. Methanol Reduction in polarity (1.85 D → 1.70 D) results in a dramatic change in physical properties. 1.85 D 1.70 D