1. What determines the state of matter a molecule is at room temperature? What determines the ability of a molecule to

1. 1. What determines the state of matter a molecule is at room temperature? What determines the ability of a molecule to develop cohesive and adhesive forces?

2. 1. What determines the state of matter a molecule is at room temperature? What determines the ability of a molecule to develop cohesive and adhesive forces? • Intermolecular forces of attraction such as london dispersion, dipole dipole attractions and hydrogen bonding determine attractions between molecules.

3. IMF • 2. What type of molecules can attract each other through London dispersion forces? • All molecules will attract each other through London Dispersion Forces • 3. What does dispersion mean? • Dispersion means to spread out • 4. How does dispersion create polarity in molecules? • One sided momentary Shifts in electrons caused by this dispersion create short lived positive and negative regions. • 5. What force of attraction causes attractions between molecules? • Positive and Negative Regions cause electrostatic attractions between molecules.

4. IMF • 2. What type of molecules can attract each other through London dispersion forces? • All molecules will attract each other through London Dispersion Forces • 3. What does dispersion mean? • Dispersion means to spread out • 4. How does dispersion create polarity in molecules? • One sided momentary Shifts in electrons caused by this dispersion create short lived positive and negative regions. • 5. What force of attraction causes attractions between molecules? • Positive and Negative Regions cause electrostatic attractions between molecules.

5. IMF • 2. What type of molecules can attract each other through London dispersion forces? • All molecules will attract each other through London Dispersion Forces • 3. What does dispersion mean? • Dispersion means to spread out • 4. How does dispersion create polarity in molecules? • One sided momentary Shifts in electrons caused by this dispersion create short lived positive and negative regions. • 5. What force of attraction causes attractions between molecules? • Positive and Negative Regions cause electrostatic attractions between molecules.

6. IMF • 2. What type of molecules can attract each other through London dispersion forces? • All molecules will attract each other through London Dispersion Forces • 3. What does dispersion mean? • Dispersion means to spread out • 4. How does dispersion create polarity in molecules? • One sided momentary Shifts in electrons caused by this dispersion create short lived positive and negative regions. • 5. What force of attraction causes attractions between molecules? • Positive and Negative Regions cause electrostatic attractions between molecules.

7. IMF • 2. What type of molecules can attract each other through London dispersion forces? • All molecules will attract each other through London Dispersion Forces • 3. What does dispersion mean? • Dispersion means to spread out • 4. How does dispersion create polarity in molecules? • One sided momentary Shifts in electrons caused by this dispersion create short lived positive and negative regions. • 5. What force of attraction causes attractions between molecules? • Positive and Negative Regions cause electrostatic attractions between molecules.

8. London dispersion forces-momentary shifts

9. London Dispersion Forces • 6. What effect does the size of a molecule have on the strength of London Dispersion Forces? Larger and heavier atoms and molecules exhibit stronger dispersion forces than smaller and lighter ones. In a larger atom or molecule, the valence electrons are, on average, farther from the nuclei than in a smaller atom or molecule. They are less tightly held and can more easily form temporary dipoles

10. London Dispersion Forces • 6. What effect does the size of a molecule have on the strength of London Dispersion Forces? Larger and heavier atoms and molecules exhibit stronger dispersion forces than smaller and lighter ones. In a larger atom or molecule, the valence electrons are, on average, farther from the nuclei than in a smaller atom or molecule. They are less tightly held and can more easily form temporary dipoles

11. IMF • F2 with a mass of 38 is a gas, • Cl2 with a mass of 71 is a gas Br2 with a mass of 160 is a liquid, I2 with a mass 254 of is a solid at room temp. These are all non polar molecules from the same group in the periodic table.

12. Dipole Dipole • 7. What type of molecules attract each other through • Dipole Dipole interactions • Molecules that contain polar covalent bonds and asymmetrical shapes have permanent positive end and a negative regions. • The permanent force of attraction between these positive and negative regions are referred to as a dipole-dipole attraction. • antoine.frostburg.edu/chem/senese/101/liquids/faq/h-bonding-vs-london-forces.shtml

13. Dipole Dipole • 7. What type of molecules attract each other through • Dipole Dipole interactions • Molecules that contain polar covalent bonds and asymmetrical shapes have permanent positive end and a negative regions. • The permanent force of attraction between these positive and negative regions are referred to as a dipole-dipole attraction. • antoine.frostburg.edu/chem/senese/101/liquids/faq/h-bonding-vs-london-forces.shtml

14. IMF • 8. What is hydrogen bonding? • It is a special case of Dipole-Dipole • Hydrogen bonded to N O F • 9. What characteristics do the atoms bonded to H have? • The Nitrogen, Oxygen and Fluorine are small highly electronegative atoms that develop substantial partial negative charges when they bond with hydrogen which in turn develops a substantial positive charge. • The partially positive hydrogen of one molecule is attracted to the partially negative portion of another molecule. • 10. Are hydrogen bonds the same as covalent bonds? • Hydrogen bonds are between molecules not within in molecules and are much weaker than covalent bonds

15. IMF • 8. What is hydrogen bonding? • It is a special case of Dipole-Dipole • Hydrogen bonded to N O F • 9. What characteristics do the atoms bonded to H have? • The Nitrogen, Oxygen and Fluorine are small highly electronegative atoms that develop substantial partial negative charges when they bond with hydrogen which in turn develops a substantial positive charge. • The partially positive hydrogen of one molecule is attracted to the partially negative portion of another molecule. • 10. Are hydrogen bonds the same as covalent bonds? • Hydrogen bonds are between molecules not within in molecules and are much weaker than covalent bonds

16. IMF • 8. What is hydrogen bonding? • It is a special case of Dipole-Dipole • Hydrogen bonded to N O F • 9. What characteristics do the atoms bonded to H have? • The Nitrogen, Oxygen and Fluorine are small highly electronegative atoms that develop substantial partial negative charges when they bond with hydrogen which in turn develops a substantial positive charge. • The partially positive hydrogen of one molecule is attracted to the partially negative portion of another molecule. • 10. Are hydrogen bonds the same as covalent bonds? • Hydrogen bonds are between molecules not within in molecules and are much weaker than covalent bonds

17. IMF • 8. What is hydrogen bonding? • It is a special case of Dipole-Dipole • Hydrogen bonded to N O F • 9. What characteristics do the atoms bonded to H have? • The Nitrogen, Oxygen and Fluorine are small highly electronegative atoms that develop substantial partial negative charges when they bond with hydrogen which in turn develops a substantial positive charge. • The partially positive hydrogen of one molecule is attracted to the partially negative portion of another molecule. • 10. Are hydrogen bonds the same as covalent bonds? • Hydrogen bonds are between molecules not within in molecules and are much weaker than covalent bonds

18. Molecules that hydrogen bond.

19. 11. How does Hydrogen Bonding affect the boiling points of molecules that can H-bond? H2O, HF, and NH3 have much higher boiling points than similar molecules because of hydrogen bonding.

20. 11. How does Hydrogen Bonding affect the boiling points of molecules that can H-bond? H2O, HF, and NH3 have much higher boiling points than similar molecules because of hydrogen bonding.

21. 12. Intermolecular Forces Questions • HBr HBr attract each by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding I and II Why? All molecules undergo momentary shifts that characterize London Dispersion Forces HBr – nm to nm E.D. 2.8 – 2.2 = .6 Polar covalent Dipole to Dipole Attractions are found between asymmetrical molecules containing polar covalent bonds

22. 12. Intermolecular Forces Questions • HBr HBr attract each by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding I and II Why? All molecules undergo momentary shifts that characterize London Dispersion Forces HBr – nm to nm E.D. 2.8 – 2.2 = .6 Polar covalent Dipole to Dipole Attractions are found between asymmetrical molecules containing polar covalent bonds

23. 12. Intermolecular Forces Questions • HBr HBr attract each by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding I and II Why? All molecules undergo momentary shifts that characterize London Dispersion Forces HBr – nm to nm E.D. 2.8 – 2.2 = .6 Polar covalent Dipole to Dipole Attractions are found between asymmetrical molecules containing polar covalent bonds

24. 12. Intermolecular Forces Questions • HBr HBr attract each by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding I and II Why? All molecules undergo momentary shifts that characterize London Dispersion Forces HBr – nm to nm E.D. 2.8 – 2.2 = .6 Polar covalent Dipole to Dipole Attractions are found between asymmetrical molecules containing polar covalent bonds

25. 13. Intermolecular Forces • CH3OH • HOCH3 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I and III IAll molecules undergo momentary shifts that characterize London Dispersion Forces III CH3OH contains a Hydrogen bonded to an oxygen which is attracted to the oxygen of a neighboring molecule which is characteristic of hydrogen bonding

26. 13. Intermolecular Forces • CH3OH • HOCH3 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I and III IAll molecules undergo momentary shifts that characterize London Dispersion Forces III CH3OH contains a Hydrogen bonded to an oxygen which is attracted to the oxygen of a neighboring molecule which is characteristic of hydrogen bonding

27. 13. Intermolecular Forces • CH3OH • HOCH3 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I and III Why? IAll molecules undergo momentary shifts that characterize London Dispersion Forces III CH3OH contains a Hydrogen bonded to an oxygen which is attracted to the oxygen of a neighboring molecule which is characteristic of hydrogen bonding

28. 13. Intermolecular Forces • CH3OH • HOCH3 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I and III Why? IAll molecules undergo momentary shifts that characterize London Dispersion Forces III CH3OH contains a Hydrogen bonded to an oxygen which is attracted to the oxygen of a neighboring molecule which is characteristic of hydrogen bonding

29. 13. Intermolecular Forces • CH3OH • HOCH3 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I and III Why? IAll molecules undergo momentary shifts that characterize London Dispersion Forces III CH3OH contains a Hydrogen bonded to an oxygen which is attracted to the oxygen of a neighboring molecule which is characteristic of hydrogen bonding

30. 14. Intermolecular Forces • CH4 CH4 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I only Why? I All molecules undergo momentary shifts that characterize London Dispersion Forces C nonmetal H nonmetal E.D 2.6 – 2.2 = .4 Nonpolar covalent Nonpolar molecules can only attract each other by nonpolar covalent bonds.

31. 14. Intermolecular Forces • CH4 CH4 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I only Why? I All molecules undergo momentary shifts that characterize London Dispersion Forces C nonmetal H nonmetal E.D 2.6 – 2.2 = .4 Nonpolar covalent Nonpolar molecules can only attract each other by nonpolar covalent bonds.

32. 14. Intermolecular Forces • CH4 CH4 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I only Why? I All molecules undergo momentary shifts that characterize London Dispersion Forces C nonmetal H nonmetal E.D 2.6 – 2.2 = .4 Nonpolar covalent Nonpolar molecules can only attract each other by nonpolar covalent bonds.

33. 14. Intermolecular Forces • CH4 CH4 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I only Why? I All molecules undergo momentary shifts that characterize London Dispersion Forces C nonmetal H nonmetal E.D 2.6 – 2.2 = .4 Nonpolar covalent Nonpolar molecules can only attract each other by nonpolar covalent bonds.

34. 14. Intermolecular Forces • CH4 CH4 • The above attract each other by • I) London Dispersion Forces • II) Dipole Dipole Attractions • III) Hydrogen bonding • I only Why? I All molecules undergo momentary shifts that characterize London Dispersion Forces C nonmetal H nonmetal E.D 2.6 – 2.2 = .4 Nonpolar covalent Nonpolar molecules can only attract each other by nonpolar covalent bonds.

35. 15. How do hydrogen bonds form between water molecules?

36. 15. How do hydrogen bonds form between water molecules?

37. 16. Why can Carbon’s form 4 equivalent covalent bonds? • It can undergo sp3 hybridization in which a 2s electron moves into a vacate 2p orbital creating an exicited state in which the 2s and the three 2p’s are half filled. • The half filled 2s and three 2p orbitals then change ( hybridize ) into 4 equivalent sp3 orbitals that allow carbon to form 4 bonds

38. 16. Why can Carbon’s form 4 equivalent covalent bonds? • It can undergo sp3 hybridization in which a 2s electron moves into a vacate 2p orbital creating an exicited state in which the 2s and the three 2p’s are half filled. • The half filled 2s and three 2p orbitals then change ( hybridize ) into 4 equivalent sp3 orbitals that allow carbon to form 4 bonds

39. 16. Why can Carbon’s form 4 equivalent covalent bonds? • It can undergo sp3 hybridization in which a 2s electron moves into a vacate 2p orbital creating an exicited state in which the 2s and the three 2p’s are half filled. • The half filled 2s and three 2p orbitals then change ( hybridize ) into 4 equivalent sp3 orbitals that allow carbon to form 4 bonds

40. sp3 hybridization

41. sp3 hybridization • www.mhhe.com/physsci/chemistry/carey5e/Ch02/ch2-3-1.html

42. 17. Where does the overlap of atomic orbitals occur when a Sigma covalent bond forms? • The overlap occurs between the two nuclei involved in the bond

43. 17. Where does the overlap of atomic orbitals occur when a Sigma covalent bond forms? • The overlap occurs between the two nuclei involved in the bond

44. 17. Where does the overlap of atomic orbitals occur when a Sigma covalent bond forms? • The overlap occurs between the two nuclei involved in the bond

45. 18. Where does the overlap occur when pi bonds form • The overlap of orbitals does not occur between the nuclei, it occurs above and below the two nuclei or in front and back of the two nuclei Atomic Oribitals Molecular Orbitals

46. 18. Where does the overlap occur when pi bonds form • The overlap of orbitals does not occur between the nuclei, it occurs above and below the two nuclei or in front and back of the two nuclei Atomic Oribitals Molecular Orbitals

47. 18. Where does the overlap occur when pi bonds form • The overlap of orbitals does not occur between the nuclei, it occurs above and below the two nuclei or in front and back of the two nuclei Atomic Oribitals Molecular Orbitals

48. 19. What type of bonds form in Ethane that contains only single bonds, ethene with a double, and ethyne with a triple? sigma C2H6 C2H4 Sigma + pi Sigma + pi + pi C2H2

49. 19. What type of bonds form in Ethane that contains only single bonds, ethene with a double, and ethyne with a triple? sigma C2H6 C2H4 Sigma + pi Sigma + pi + pi C2H2

50. 19. What type of bonds form in Ethane that contains only single bonds, ethene with a double, and ethyne with a triple? sigma C2H6 C2H4 Sigma + pi Sigma + pi + pi C2H2