Triple Point Plot melting freezing liquid solid Pressure (atm) vaporization condensation Pressure (atm) 0.6 2.6 sublimation deposition gas Temperature (oC) LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 488

Triple Point 22,058 Critical point Critical pressure Normal melting boiling point 101.3 Pressure (KPa) Solid Liquid Vapor Remind students of the effects of temperature and pressure on the state of matter. Students are familiar with the three states ofwater. What happens to the boiling point of water as pressure increases? (It increases.) What happens to the freezing point as the pressure increases? (It decreases.) What is the triple point (The temperature and pressure at which all three states coexist in equilibrium.) 0.61 Triple point 0.016 100 373.99 Critical temperature Temperature (oC)

Objectives - Matter Explain why mass is used as a measure of the quantity of matter. Describe the characteristics of elements, compounds, and mixtures. Solve density problems by applying an understanding of the concepts of density. Distinguish between physical and chemical properties and physical and chemical changes. Demonstrate an understanding of the law of conservation of mass by applying it to a chemical reaction.

Objectives - Energy Identify various forms of energy. Describe changes in energy that take place during a chemical reaction. Distinguish between heat and temperature. Solve calorimetry problems. Describe the interactions that occur between electrostatic charges.

Law of Conservation of Energy Eafter = Ebefore 2 H2 + O2  2 H2O + energy Energy Changes +  + WOOF!

Law of Conservation of Energy Eafter = Ebefore 2 H2 + O2  2 H2O + energy Energy Changes +  + WOOF! ENERGY CO2 + H2O C2H2 + O2 PEreactants PEproducts KEstopper heat, light, sound

Law of Conservation of Energy Eafter = Ebefore 2C2H2 + 5O2  4 CO2 + 2H2O + energy Energy Changes ENERGY C2H2 + O2 PEreactants PEproducts KEstopper heat, light, sound

Heating Curves Gas - KE  Boiling - PE  Liquid - KE  Melting - PE  140 Gas - KE  120 100 Boiling - PE  80 60 40 Liquid - KE  Temperature (oC) 20 Melting - PE  -20 -40 Solid - KE  -60 -80 -100 Time

Heating Curves Temperature Change change in KE (molecular motion) depends on heat capacity Heat Capacity energy required to raise the temp of 1 gram of a substance by 1°C “Volcano” clip - water has a very high heat capacity Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Heating Curves Phase Change change in PE (molecular arrangement) temp remains constant Heat of Fusion (Hfus) energy required to melt 1 gram of a substance at its m.p. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Phase Diagrams Show the phases of a substance at different temps and pressures. Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem