1 / 13

Ch. 10: Liquids and Solids

Ch. 10: Liquids and Solids. 10.1 Intermolecular Forces Read this section!!! Students frequently get confused and they like to ask about this topic on the AP Exam!!!. Intra- vs. Inter-. intramolecular forces inside molecules hold atoms together in a molecule intermolecular forces

belita
Download Presentation

Ch. 10: Liquids and Solids

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. Ch. 10: Liquids and Solids 10.1 Intermolecular Forces Read this section!!! Students frequently get confused and they like to ask about this topic on the AP Exam!!!

  2. Intra- vs. Inter- • intramolecular forces • inside molecules • hold atoms together in a molecule • intermolecular forces • between different molecules • get weaker as phase changes from S – L – G • When a substance changes state, molecule stays together but intermolecular forces weaken

  3. Examples • Intramolecular Forces • Covalent Bonding • Ionic Bonding • Metallic Bonding • MUCH STRONGER • Intermolecular Forces – only occur between different molecules • Dipole-Dipole Interactions • Hydrogen Bonding • London Dispersion Forces • MUCH WEAKER

  4. Dipole-Dipole Attraction • when molecules with dipole moments line up to minimize repulsion and maximize attraction • very weak compared to covalent and ionic bonds

  5. Hydrogen Bonding • happens between H and N, O, or F • very strong type of dipole-dipole attraction • because bond is so polar • because atoms are so small

  6. London Dispersion Forces • in every molecular compound • only important for nonpolar molecules and noble gas atoms • weak, short-lived • caused by formation of temporary dipole moments

  7. Intermolecular Forces • Strongest  H bonding • Next Strongest  Dipole-Dipole • Weakest  London Dispersion • Why important?? Influences boiling points, melting points, etc….

  8. Figure 10.4 The Boiling Points of the Covalent Hydrides of the Elements in Groups 4A, 5A, 6A, and 7A

  9. Practice • which has highest boiling pt? • HF, HCl, or HBr? (H-Bonding) • Identify the most important Forces : • BaSO4 • H2S • Xe • C2H6 • P4 • H2O • CsI ionic dipole-dipole H-bonding London Dispersion

  10. CO2 or OCS CO2: nonpolar so only LD OCS: polar so dipole-dipole PF3 or PF5 PF3: polar so dipole-dipole PF5: nonpolar so only LD SF2 or SF6 SF2: polar so dipole-dipole SF6: nonpolar so only LD SO3 or SO2 SO3: nonpolar so LD only SO2: polar so dipol-dipole Which has stronger IMF’s?

  11. Ch. 10: Liquids and Solids 10.2 Liquids

  12. Properties of Liquids • low compressibility • no rigidity • high density compared to gases • beads up as droplets • molecules on surface are subject to attractions from side and below • surface tension • resistance to an increase in surface area • greater tension means stronger IMF’s

  13. Properties of Liquids • capillary action • spontaneous rising of a liquid up a tube • from cohesive forces (IMF’s) and adhesive forces (between liquid and container) • viscosity • measure of a liquid’s resistance to flow • strong IMF’s  highly viscous • large, complex molecules  highly viscous

More Related