Solids and Liquids Chapter 14

Kinetic Molecular Theory Solids-particles are highly ordered and packed closely together. They have slight vibrational movement. A solid maintains its shape regardless of the container. Liquids-particles are more disordered and are spread further than in a solid. They more closely resemble solids than gases.

Phases Heat is added Heat is removed Endo Exo Condensing-gas to liquid Freezing-liquid to solid (0°C for water-freezing point) Deposition-gas to solid (water vapor directly to ice) Evaporation-liquid to gas (100°C for water-boiling point) Melting-solid to liquid Sublimation-solid to gas (dry ice directly to a gas)

It takes 7 times more energy to vaporize a mole of water than to melt a mole of water.

Phase Diagram of Water

One gram of ice has a greater volume than one gram of water. liquid water 1.00g = 1.00g/mL 1.00mL solid water 1.00g = 0.917g/mL 1.09mL

All phase changes are physical changes because a new substance is not created.

What keeps the molecules together? Intramolecular forces (within the molecule)-holds the atoms of a molecule together Ex: H bonds with O to make H2O Intermolecular forces (between the molecules)-forces between molecules Ex: H2O bonds are broken with other H2O molecules when making steam.

Intermolecular Forces Hydrogen bonding-special type of strong dipole-dipole bond where H is bonded to a highly electronegative element Ex: H2S, HCl Dipole-dipole attraction-polar molecules line up so the positive and negative poles attract (1% as strong as covalent or ionics) London dispersion forces-forces that exist among noble gas atoms and nonpolar molecules (weakest force) Ex: H2, N2, I2

Intermolecular Forces: Hydrogen Bonding Forces Click in this box to enter notes. Go to Slide Show View (press F5) to play the video or animation. (To exit, press Esc.) This media requires PowerPoint® 2000 (or newer) and the Macromedia Flash Player (7 or higher). [To delete this message, click inside the box, click the border of the box, and then press delete.] Copyright © Houghton Mifflin Company. All rights reserved.

Types of crystalline solids Ionic-contains cations and anions, conduct electricity Ex: Salt (NaCl). Have high melting points. Molecular-contains covalent bonds (molecules) Ex: Sugar (C12H22O11). Intermolecular forces are weak so they melt at low temperatures. Atomic-1 element covalently bonded to itself Ex: Diamond (Carbon)

Structure of an Ionic Solid (NaCl) Click in this box to enter notes. Go to Slide Show View (press F5) to play the video or animation. (To exit, press Esc.) This media requires PowerPoint® 2000 (or newer) and the Macromedia Flash Player (7 or higher). [To delete this message, click inside the box, click the border of the box, and then press delete.] Copyright © Houghton Mifflin Company. All rights reserved.

Molecular Solids Click in this box to enter notes. Go to Slide Show View (press F5) to play the video or animation. (To exit, press Esc.) This media requires PowerPoint® 2000 (or newer) and the Macromedia Flash Player (7 or higher). [To delete this message, click inside the box, click the border of the box, and then press delete.] Copyright © Houghton Mifflin Company. All rights reserved.

Comparison of a Molecular Compound and an Ionic Compound Click in this box to enter notes. Go to Slide Show View (press F5) to play the video or animation. (To exit, press Esc.) This media requires PowerPoint® 2000 (or newer) and the Macromedia Flash Player (7 or higher). [To delete this message, click inside the box, click the border of the box, and then press delete.] Copyright © Houghton Mifflin Company. All rights reserved.

Metallic Solids Metals have strong, nondirectional bonding. Electron sea model-metal atoms are located in a sea of valence electrons that are shared Alloy-a substance that contains a mixture of elements and has metallic properties.

Alloys Substitutional alloy-metal atoms are replaced by other metal atoms of similar size Ex: sterling silver (93% silver, 7% copper) Analogy: Substitute teacher Interstitial alloy-some of the interstices (holes) among metal atoms are occupied by smaller atoms Ex: steel (carbon and iron) Analogy: Tutor

Electron Sea Model Click in this box to enter notes. Go to Slide Show View (press F5) to play the video or animation. (To exit, press Esc.) This media requires PowerPoint® 2000 (or newer) and the Macromedia Flash Player (7 or higher). [To delete this message, click inside the box, click the border of the box, and then press delete.] Copyright © Houghton Mifflin Company. All rights reserved.