SOLID LIQUID GAS Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide past each other Well separated with no regular arrangement. Vibrate and move freely at high speeds What causes a substance to be in solid or liquid state? Attractive forces between particles.

SOLID LIQUID GAS Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide past each other Well separated with no regular arrangement. Vibrate and move freely at high speeds How do we overcome these attractive forces? By adding energy (heat) to the particles.

Temperature Energy Added solid liquid gas 100º C - 0º C - melting point (s)  (l)- (s)  (l)- freezing point boiling point (l)  (g)- (l)  (g)- condensation point

Temperature Energy Added Heat of fusion Heat of vaporization “Fusion” means melting (fusing bits of solid into a liquid) when it is used to talk about phase changes. ∆H fusion ∆H vaporization

Temperature Energy Added  Kinetic energy (T) does not increase during phase change.  The energy that overcomes attractive forces between particles is stored as potential energy. 0º C - -25º C - Heating solid (kinetic energy) Latent heat (heat of fusion) (potential energy) Heating liquid (kinetic energy) Latent heat (heat of vaporization) (potential energy)  Phase change energy is often called a “latent” heat. (Latent = hidden) Heating gas (kinetic energy) 100º C - 165º C -

Kinetic Energy = temperature

60 ºC 80 ºC 100 ºC 120 ºC

 Does spaghetti take more time or less time to cook in Alpine, compared to San Diego?  MORE time– because we cook it at a slightly lower temperature.

Temperature Pressure

Temperature Pressure SOLID GAS LIQUID

Temperature Pressure SOLID GAS LIQUID Every point on this line is a MP & FP ! Every point on this line is a BP & CP !

Temperature Pressure SOLID GAS LIQUID Every point on this line is a SP & DP !

Requires the input of energy Sublimation of snow occurs more readily under at high altitudes with less air pressure, with dry winds. Examples: dry ice, iodine and snow Sublimation occurs (on a small scale) in your freezer– when things get freezer burn.

(The opposite of sublimation) Deposition of iodine  Requires the release of energy.  Deposition commonly occurs when water vapor freezes to form snow or frost.  (On your windshield, for example.)  This also occurs in your freezer with the freezer burn!

Temperature Pressure SOLID GAS LIQUID

Temperature Pressure SOLID GAS LIQUID

Temperature Pressure SOLID GAS LIQUID

 The 1 atm line crosses all three phases, so we experience all phases of water.  To reach the triple point, you would need a vacuum chamber. (Or extreme high altitude.)

 As altitude increases, air pressure decreases.  As air pressure decreases boiling point decreases. At what altitude would your food cook most quickly?  Hint: at what temperature would it cook most quickly?

 This is why boiling ramen doesn’t work well for (high altitude) High Adventure camps  The boiling water is not as hot as you hoped… so cooking takes forever.

Temperature Energy Added solid liquid gas 85º C - 2º C - melting point (s)  (l)- (s)  (l)- freezing point boiling point (l)  (g)- (l)  (g)- freezing point Even in a raging bonfire, your water will refuse to get any hotter once it’s boiling. 

 If only there was a way to increase the pressure…  They can boil water at a temp above 100 ºC, so food cooks faster. Pressure cookers do that!

 Condensation can occur when molecules go from gas to liquid at temperatures below the boiling point.  Molecules slow down and begin to stick together. (Due to IMFs!)  As they change from gas to liquid, the molecules release latent heat to the surroundings   Condensation is a heating process!  The release of energy from condensation drives weather including wind, thunderstorms, hurricanes etc…