1. Agenda 3/27/2015 Slip Quiz Part 1 Gas Law Calculations continued. SGCM States of Matter (Chapter 13) – Intermolecular Forces and Phase Changes – Discussion/mini labs – Homework Slip quiz Part 2

2. 1 st 5 mins – Slip-Quiz 1.Write the chemical formula for water and then draw a ball and stick model to show the shape of the molecule. 2. Indication of an atom’s ability to attract electrons in a chemical bond is A.Ionization energyB. buffer capacity C. polarityD. electronegativity

3. 1 st 5 mins – Slip-Quiz 1.Write the chemical formula for water and then draw a ball and stick model to show the shape of the molecule. H 2 Ov-shaped 2. Indication of an atom’s ability to attract electrons in a chemical bond is A.Ionization energyB. buffer capacity C. polarityD. electronegativity

4. Gas Law Calculations 1-10 Quick correct Gas Law Calculations continued. Quick do – 10: 30 stop

5. Study Guide for Content Mastery Section 13.2 Forces of Attraction 1. Ionic, metallic and covalent bonds are examples of what type of forces?

6. Study Guide for Content Mastery Section 13.2 Forces of Attraction 1.Ionic, metallic and covalent bonds are examples of what type of forces? Intramolecular forces – they hold atoms together so that they are held together in molecules (forces exist within the molecule itself)

7. Study Guide for Content Mastery Section 13.2 Forces of Attraction 2. Dispersion forces, dipole-dipole forces, and hydrogen bonds are examples of what type of forces?

8. Study Guide for Content Mastery Section 13.2 Forces of Attraction 2. Dispersion forces, dipole-dipole forces, and hydrogen bonds are examples of what type of forces? Intermolecular forces – these forces exist between molecules (in between molecules, holding them in “loose” groups)

9. Study Guide for Content Mastery Section 13.2 Forces of Attraction 3. Describe dispersion forces. Dispersion forces are

10. Study Guide for Content Mastery Section 13.2 Forces of Attraction 3. Describe dispersion forces. Dispersion forces are weak intermolecular forces that result from temporary shifts in the density of electrons in electron clouds in the molecules. The more electrons there are to “shift” the stronger the possible dispersion forces will be.

11. Study Guide for Content Mastery Section 13.2 Forces of Attraction 4. Dispersion forces are greatest between what type of molecules? “Dispersion forces are the dominant force of attraction between identical non-polar molecules.” p. 394 This is only because there are no other possible intermolecular attractions.

12. Study Guide for Content Mastery Section 13.2 Forces of Attraction 4. Dispersion forces are greatest between what type of molecules? More useful question is “When are dispersion forces greatest?” Dispersion forces “can have a noticeable effect as the number of electrons involved increases.” p 394

14. Study Guide for Content Mastery Section 13.2 Forces of Attraction 5. Describe a permanent dipole.

15. Study Guide for Content Mastery Section 13.2 Forces of Attraction 5. Describe a permanent dipole. A permanent dipole contains regions that always have a slightly negative charge and regions that always have a slightly positive charge. (Charge separation is less than it would be in a full ionic bond.) Permanent unequal sharing of electrons in covalent bonds. Depends on relative electronegativity values.

16. Study Guide for Content Mastery Section 13.2 Forces of Attraction 5. Describe a permanent dipole. Note that a molecule that has a permanent dipole is said to be a polar molecule.

17. Study Guide for Content Mastery Section 13.2 Forces of Attraction 6. Describe dipole-dipole forces. Dipole-dipole forces are the intermolecular attractions that occur between oppositely charged regions of polar molecules. Dipole-dipole forces are stronger, and last longer than dispersion forces.

18. Study Guide for Content Mastery Section 13.2 Forces of Attraction 7. Describe a hydrogen bond. A hydrogen bond is a special case of a dipole-dipole attraction that only occurs between molecules that each contain a hydrogen atom bonded to a small, highly electronegative atoms (F, N, O) with at least one lone electron pair. H-FH 2 ONH 3

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

20. Drops of water on a penny? Intermolecular forces – attractions in between molecules Float a paper clip? Add a drop of liquid soap.

21. Study Guide for Content Mastery Section 13.2 Forces of Attraction 8. Identify each of the diagrams below as illustrating dipole-dipole forces, dispersion forces, or hydrogen bonds. Not sure how you’re supposed to tell that a. has the Hydrogen bonds, b shows only temporary distortion of electron clouds leading to dispersion forces, so c must be dipole-dipole.

22. Study Guide for Content Mastery Section 13.2 Forces of Attraction 9. Rank dipole-dipole forces, dispersion forces, and hydrogen bonds in order of increasing strength. Weakest intermolecular force is dispersion, dipole-dipole forces are stronger, and hydrogen bonds strongest. (All much weaker than covalent or ionic bonds.)

23. Study Guide for Content Mastery Section 13.3 Liquids and Solids 1.The constant motion of the particles in a liquid causes the liquid to take the shape of the container. ✔ 2.At room temperature and one atmosphere of air pressure, the density of a liquid is much greater than that of its vapor. ✔

24. Study Guide for Content Mastery Section 13.3 Liquids and Solids 3.Liquids are not easily compressed because their particles are loosely tightly packed. NOW its ✔ 4. A liquid is less flud than a gas because intramolecular intermolecular attractions interfere with the ability of particles to flow past one another. Now its ✔

25. Study Guide for Content Mastery Section 13.3 Liquids and Solids 5.Liquids that have stronger intermolecular forces have higher viscosities than do liquids with weaker intermolecular forces. ✔ 6.The viscosity of a liquid increases decreases with temperature increases because the increased average kinetic energy of the particles makes it easier for the particles to flow. Now its ✔

26. Study Guide for Content Mastery Section 13.3 Liquids and Solids 7. Liquids that can form hydrogen bonds generally have high surface tension. ✔ 8. A liquid that rises in a narrow glass tube shows that the adhesive forces between the particles of the liquid and glass are greater than the cohesive forces between the particles of the liquid. ✔

27. Adhesion vs. Cohesion adhesion

28. Study Guide for Content Mastery Section 13.3 Liquids and Solids 9. Solids have a definite shape and volume because the motion of their particles is limited to vibrations around fixed locations. ✔ 10. Most solids are less more dense than liquids because the particles in a solid are more closely packed than those in a liquid. Now its ✔

29. Study Guide for Content Mastery Section 13.3 Liquids and Solids 11. Rubber is a crystalline an amorphous solid because its particles are not arranged in a regular, repeating pattern. Now its ✔

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

31. Study Guide for Content Mastery Section 13.4 Phase Changes Phase change PhaseEnergy InitialFinalRequiredreleased CondensationGasLiquid ✔ DepositionGasSolid ✔ FreezingLiquidSolid ✔ MeltingSolid liquid ✔ SublimationSolidgas ✔ Vaporizationliquidgas ✔

32. Transitions Between Phases 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?

33. Study Guide for Content Mastery Section 13.4 Phase changes 7. Temperature at which a liquid is converted into a crystalline solid – freezing point. 8. Temperature at which the forces holding a crystalline lattice together are broken. – melting point. 9. Temperature at which the vapor pressure of a liquid equals the external or atmospheric pressure – boiling point.

34. Phase Diagram for H 2 O Region II Region III Region I 3 ·2 A 4

35. Study Guide for Content Mastery Section 13.4 Phase changes 10. What variables are plotted on a phase diagram? Temperature and Pressure. 11. a) Region I vapor b) Region II solid c) Region III liquid 12. Point 2 is the normal freezing point of water. 13. The temperature at point 3 is 100.00°C

36. Study Guide for Content Mastery Section 13.4 Phase changes 14. Line A represents the temperatures and pressures at which solid water and water vapor coexist. 15. What is point 4 called? What does it represent? Point 4 is called the critical point and it represents the pressure and temperature above which water cannot exist as a liquid.

37. Objective: Picture intermolecular forces present in solids and liquids (dispersion forces) and relate these forces to volatility and boiling/melting point temperatures. http://www.chemguide.co.uk/atoms/bonding /vdw.html http://www.chemguide.co.uk/atoms/bonding /vdw.html http://phet.colorado.edu/en/simulation/mole cule-polarity http://phet.colorado.edu/en/simulation/mole cule-polarity Adhesion/cohesion

38. Homework 1)From textbook Chemistry: Matter and Change p390 problem-solving LAB How are the depth of a dive and pressure related? Plot the graph (use a ruler and pencil only) then answer all 4 questions (Analysis and Critical thinking) Pressure Versus Depth Depth of dive (m) Pressure (atm) 102.0 203.0 304.0 405.0 506.0 607.0 Depth (m) (independent variable) Pressure (atm) Pressure versus Depth for Dives. Adjust your scale to use as much of the graph paper as possible. Points + or ʘ 2. www.chemistrymc.com Chapter Test – Chapter 13 post your score pdf to google classroom. SLG test will be next Friday.www.chemistrymc.com

39. Slip-Quiz Part 2 Draw 3 diagrams to show the arrangement of particles in a typical solid, liquid and gas.