States of Matter Solid Liquid Gas definite volume definite shape regular geometric pattern crystalline structure vibrate in a fixed location strong forces of attraction Molecules far apart no definite shape no definite volume no force of attractions Compressible Completely fills its container Molecules farther apart definite volume no definite shape intermolecular forces noncompressible

GAS LIQUID SOLID condense Entropy decrease Entropy Increase Boiling Evaporation vaporization LIQUID freezing Crystallization solidification Melting Fusion SOLID Sublimation Phase change from solid to gas Examples-- CO2(s) I2 (s) Entropy amount of disorder How messy the molecules are Deposition Change from a gas to a solid Example --- snow

Phase Diagrams Heating Curve G boiling boiling BP L & G Temp L melting S & L S Time (heat added)

Melting Point Boiling Point the temperature at which the solid and liquid phase of a substance are in equilibrium --- also freezing point Water 0oC the temperature at which the liquid and gas phase of a substance are in equilibrium --- also condensation point Water 100oC

Cooling Curve L & G condensation freezing Time (heat removed)

Average kinetic energy or speed of the molecules Units: C or K Heat Temperature Potential Energy Average kinetic energy or speed of the molecules Units: C or K Stored energy Energy that is contained within a bond Energy associated with phase changes A form of energy Units: Joule calorie Heat can be transferred from one object to another Heat flows from hot to cold ( high temp to low temp) Types of energy: -chemical (bonds breaking/forming) -mechanical- movement, machine -electrical- transport of e-’s -thermal- heat transfer -nuclear- mass to energy Exothermic Endothermic Release heat or energy Energy is given off Absorb heat or energy Energy is taken in

Phase Diagrams Heating Curve  PE No change KE KE No change PE KE temperature at which the vapor pressure of the solid equals the vapor pressure of the liquid  PE No change KE G KE No change PE boiling BP L & G Temp L KE No change PE  PE No change KE melting MP S & L S the temperature at which the vapor pressure of the liquid equals the atmospheric pressure above the liquid KE No change PE Time (heat added)

Cooling Curve  KE No change PE L & G  KE  PE No change PE condensation  KE No change PE  PE No change KE freezing  KE No change PE  PE No change KE

GAS LIQUID SOLID condense freezing Evaporation vaporization Boiling Evaporation vaporization Entropy Increase Entropy decrease condense Absorb energy endo Release energy exo LIQUID Melting Fusion freezing Crystallization solidification SOLID Sublimation Phase change from solid to liquid Examples-- CO2(s) I2 (s) Entropy amount of disorder How messy the molecules are Deposition Change from a gas to a solid Example --- snow

Vapor Pressure The pressure vapor exerts over it’s liquid on a closed system. The more liquid that evaporates, the higher the vapor pressure! Vapor pressure is temp. dependent. Up temp = up Vapor Pressure If no cap- open system- VP= atm pressure

Boiling Boiling occurs when atmospheric pressure = vapor pressure. Increase atmospheric pressure you increase boiling point. Stronger intermolecular forces = higher BP A normal boiling point- temperature when something boils at standard pressure 101.3 kPa.

The point at which all 3 states of matter can exist at the same time Occurs at the end of the l/g line Can not distinguish between a liquid and a gas Positive: the solid is more dense than the liquid (sink) Negative: the solid is less dense than the liquid (float)