1 / 30

INTERMOLECULAR FORCES

INTERMOLECULAR FORCES. Chap. 13: Day 2. Generally strongest “Interparticle” Ionic Bond Ion-ion force Metalic bond Electronic force. Generally weaker “intermolecular forces” Covalent bonds Polar molecules Dipole forces Nonpolar molecules London Disperson Induced dipole forces.

zareh
Download Presentation

INTERMOLECULAR FORCES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. INTERMOLECULAR FORCES Chap. 13: Day 2

  2. Generally strongest “Interparticle” Ionic Bond Ion-ion force Metalic bond Electronic force Generally weaker “intermolecular forces” Covalent bonds Polar molecules Dipole forces Nonpolar molecules London Disperson Induced dipole forces Type of Bond determines Forces

  3. Melting Point Energy needed over come the intermolecular forces between molecules in the solid phase Temperature at which molecules in a solid gain enough potential energy to change position (become L)

  4. Boiling Point Energy needed over come the intermolecular forces between molecules in the liquid phase Temperature at which molecules in a liquid gain enough potential energy to change position (become gas)

  5. POLAR vs NONPOLAR

  6. Molecular Polarity Molecules will be polar if a) bonds are polar AND • the molecule is NOT “symmetric”

  7. Polar or Nonpolar? Compare CO2 and H2O. Which one is polar?

  8. Polar or Nonpolar? • Consider AB3 molecules: BF3, Cl2CO, and NH3.

  9. Molecular Polarity, BF3 B atom is positive and F atoms are negative. B—F bonds in BF3 are polar. But molecule is symmetrical and NOT polar

  10. Molecular Polarity, HBF2 B atom is positive but H & F atoms are negative. B—F and B—H bonds in HBF2 are polar. But molecule is NOT symmetrical and is polar.

  11. Is Methane, CH4, Polar? Methane is symmetrical and is NOT polar.

  12. Substituted Ethylene • C—F bonds are MUCH more polar than C—H bonds. • Because both C—F bonds are on same side of molecule, molecule is POLAR.

  13. NONPOLAR Molecules What causes the differences in intermolecular forces between molecules? Why do the intermolecular forces vary between nonpolar molecules?

  14. Solid Liquid WHY?

  15. Bigger Molecules interact more

  16. DISPERSION FORCE Nonpolar Molecules

  17. POLAR Molecules Why do the intermolecular forces vary between polar molecules?

  18. Figure 9.15 Molecular Polarity Molecules—such as HCl and H2O— can be POLAR (or dipolar). They have a DIPOLE MOMENT. The polar HCl molecule will turn to align with an electric field.

  19. DIPOLE FORCE Polar Molecules

  20. More polar stronger force

  21. Why different? liquid gas

  22. ?

  23. SOME POLAR Molecules Have “special” Dipole force with Hydrogen HYDROGEN FORCE or HYDROGEN BOND

  24. HYDOGEN BOND NEED TO BE POLAR H is attached to N, F,orO

  25. ALL molecules have LONDON DISPERSION force

  26. Graphing: Intermolecular Forces • See handout • 4 different Families • Boiling point vs period 400 k Boiling point 100 k 2 period 6

More Related