1. Agenda 2/20/2013 Slip Quiz Part 1 Check - Homework Problem-solving LAB How are the depth of a dive and pressure related?(Turn in) States of Matter (Chapter 13) – Intermolecular Forces continued – What’s going on in milk? Phase Changes – additional notes VIP Chapter 13 Assessment pages (group brain) Slip quiz Part 2

2. 1 st 5 mins – Slip-Quiz 1.Write the chemical formula for ammonia and then draw a ball and stick model to show the shape of the molecule. 2. The energy required to completely remove an electron from a gaseous atom is called the element’s A.Ionization energyB. buffer capacity C. polarityD. electronegativity

3. 1 st 5 mins – Slip-Quiz 1.chemical formula for ammonia NH 3 Shape – trigonal pyramidal

4. 1 st 5 mins – Slip-Quiz 2. The energy required to completely remove an electron from a gaseous atom is called the element’s A.Ionization energyB. buffer capacity C. polarityD. electronegativity

5. Agenda 2/20/2013 Slip Quiz Part 1 Check - Homework Problem-solving LAB How are the depth of a dive and pressure related?(Turn in) States of Matter (Chapter 13) – Intermolecular Forces continued – What’s going on in milk? Phase Changes – additional notes VIP Chapter 13 Assessment pages (group brain) Slip quiz Part 2

6. Problem-solving LAB How are the depth of a dive and pressure related? Name Mrs. Day- Blattner Chemistry date 2 4 6 8 10 Pressure (atm) Depth (m) 10 20 6090 Pressure versus Depth for Dives.

7. 4. Slope = Δy = 7atm – 2 atm Δx 60m – 10 m = 5 atm = 0.1 atm /m 50m If p = pressure (atm), d = depth (m) p atm= 0.1atm/m(dm) + 1atm Good idea: Check value of p for d = 162 m p = 0.1 (162) + 1 = 17.2

8. Draw what you see. 3 colors, 3 drops each Use camera to record what happens Be ready to describe in words what you saw and photographed/video “taped” Food coloring on milk?

9. Milk on the move Intermolecular forces – attractions in between molecules

10. Hydrogen bonding in water Accounts for relatively high melting point, boiling point, properties as a solvent

11. Super hydrophobic spray http://www.youtube.com/watch?v=7is6r6zXFDc Objective: (7c) energy is released when a material condenses or freezes and is absorbed when a material evaporates or melts.

12. Phase Change Lab – Melting Ice

13. Transitions Between Phases – that require energy (absorb energy) Endothermic Solid liquid gas vaporization melting Energy (or enthalpy, H) Why we sweat- to remove energy from our bodies, cool us down

14. Transitions Between Phases Endothermic Solid liquid gas vaporization melting Energy (or enthalpy H)

15. Transitions Between Phases - endothermic Solid liquid gas vaporization melting Energy (or enthalpy H) sublimation Why do those cans you use to clean your keyboard feel so cold when you use them?

16. Transitions Between Phases that release energy –exothermic Solid liquid gas Energy (or enthalpy H) These physical changes are -ΔH exothermic

17. Transitions Between Phases that release energy Solid liquid gas condensation freezing Energy (or enthalpy H) -ΔH Exothermic Physical processes deposition

18. 13.4 Phase Changes Melting point - of a crystalline solid is the temperature at which the forces holding its crystal lattice together are broken and it becomes a liquid. Liquid phase and solid phase of a given substance can coexist. (melting point of amorphous solid, difficult to specify, tend to melt over a range of temperatures, act like liquids even when still in the solid state). NOTES 2/20/2013 Objectives – explain how the addition and removal of energy can cause a phase change; interpret a phase diagram

19. Boiling Point “The temperature at which the vapor pressure of a liquid equals the external or atmospheric pressure is called the boiling point.” (p. 406) Vapor phase and liquid phase coexist. At the specific boiling point temperature of a liquid, molecules throughout the liquid have enough energy to vaporize. Bubbles of vapor can form below the surface (rolling boil).

20. http://www.chem4kids.com/files/matter_changes.html Melting point

21. Energy Distribution of Molecules in a Liquid

22. Energy is needed (required) to melt solids The amount of energy required to melt a solid depends on the strength of the forces holding the particles together in the solid For ice to melt the ice has to be able to absorb enough energy to overcome (break) the hydrogen-bonds that hold water molecules in the crystalline structure we call “ice.” Notice that when ice melts, the covalent bonds holding the H and O atoms together in the H 2 O molecules themselves are not being affected (broken)

23. Energy is needed (required) to melt solids For salt (NaCl) to melt the salt has to be able to absorb enough energy to overcome (break) the actual ionic bonds (electrostatic attractions) that hold all the sodium (Na + ) ions and chloride (Cl - ) ions together in the crystal lattice This requires a great deal of energy Ionic compounds typically have very high melting points

24. Energy is needed (required) to melt solids and evaporate liquids For many covalent compounds the energy required to melt the solid and even to evaporate the liquid is so low that the substance is already a gas at room temperature Methane (CH 4 ) Ethane (C 2 H 6 ) Propane (C 3 H 8 ) Butane (C 4 H 10 ) Ammonia (NH 3 )

25. Energy is needed (required) to sublime solids Sublimation – direct change from solid phase to the gas phase without first become a liquid Solid iodine and solid carbon dioxide (dry ice) sublime at room temperature 25°C ( K) Ice cubes shrink in a freezer over time because they also sublime Freeze drying? + 2 reasons its useful. K = °C + 273

26. Energy is needed (required) to sublime solids Sublimation – direct change from solid phase to the gas phase without first become a liquid Solid iodine and solid carbon dioxide (dry ice) sublime at room temperature 25°C (298K) Ice cubes shrink in a freezer over time because they also sublime Freeze drying? + 2 reasons its useful. K = °C + 273 0K0K 25 °C 273K 0 °C 298K

27. Phase Diagrams (p. 408-409) The phase of a substance is controlled by temperature and pressure together A graph of pressure P (y axis) versus temperature T (x axis) Shows in which phase a substance exists under different conditions of T and P

28. On a phase diagram the triple point is the temperature at which the three phases of a substance can coexist The critical point is the pressure and temperature above which a substance cannot exist as a liquid.

29. Phase Diagram for H 2 O

30. Chapter 13 – Assessment Pages Work on in groups, discuss, agree, check in notes/text. For extended answers – discuss then answer in your own words, not a “group answer.”

31. Homework Question sheet – needs MLA format at top of page, and title is “States of Matter: CST type assessment questions.” Finish Chapter 13 Assessment Questions worked on in class today and rest of sheets. If work “with” someone else, still responsible for an original answer (in your own words) to the extended response questions. Due Tuesday 26 th, 2013 (Lab on Friday, don’t need binders)

32. Slip-Quiz Part 2 1.Which of the following is an example of an endothermic physical process? A combustion of gasolineB freezing water C photosynthesis of glucose D evaporation 2. Write an expression for the kinetic energy of a particle of mass m with velocity v.