Ch16_Part 1_complete_071211

Ch16_Part 1_complete_071211 - Chapter #16 Liquids and...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter #16 – Liquids and Solids 16.1) Intermolecular Forces 16.2) The Liquid State 16.3) An Introduction to Structures and Types of Solids 16.4) Structure and Bonding of Metals 16.5) Carbon and Silicon: Network Atomic Solids 16.6) Molecular Solids 16.7) Ionic Solids 16.8) Structures of Actual Ionic Solids 16.9) Lattice Defects 16.10) Vapor Pressure and Changes of State 16.11) Phase Diagrams 16.12) Nanotechnology
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Macroscopic Properties of Gases, Liquids, and Solids “Condensed States of Matter”
Background image of page 2
Solids, liquids and gases Intermolecular forces occur between molecules, not within molecules (as in bonding). When a molecule changes phases it remains intact – the molecule does not change, just the forces among the molecules around it.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What determines the temperature at which liquids boil and solids melt? Intra molecular forces: chemical bonds holding atoms together in a molecule ionic bonds, e.g. Na + Cl - ~400 - 4000 kJ/mol covalent bonds, e.g. H 2 , CH 4 , etc. ~150 - 1200 kJ/mol (the O-H bond energy in H 2 O is 500 kJ/mol) metallic bonds, e.g. Au, Fe, etc. ~75 - 1000 kJ/mol Inter molecular forces: forces between molecules Much weaker : ~0.05 - 40 kJ/mol Intermolecular Forces
Background image of page 4
Figure 16.44 Figure 16.6 Intermolecular forces determine: Boiling Point/Melting Point Vapor Pressure Viscosity (measure of a liquid’s resistance to flow) Surface Tension (resistance of a liquid to an increase in its surface area) Stronger forces require more energy to disrupt intermolecular interactions
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Types of Intermolecular Forces Dipole-Dipole forces Based on charge-charge interactions Fall off rapidly over distance (relatively unimportant in the gas phase) Occur in molecules with polar bonds and dipole moments (H-N, H-O, H-F) Typically 5-25 kJ/mol Figure 16.2
Background image of page 6
A special type of dipole-dipole force. Occurs when a Hydrogen atom is bound to the highly electronegative atoms O , N , or F , which have lone pairs (let’s call these atoms X or Z ). These H - X bonds are very polar ( think HF ). The partially positive H atom from one unit is attracted to the partially negative X atom from another unit (or to another partially negative atom, Z ). This is the hydrogen bond. To occur, the atom sequence must be - Z : H - X - , where both Z and X are one of the following three highly EN atoms: O , N , or F . Even though the strength of one H bond may be small, the combined strength of many H bonds can be large. Hydrogen Bonding
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Figure 16.3 Water has particularly strong hydrogen bonding intermolecular forces Hydrogen bonding: Typically 10 - 40 kJ/mol (+0.46) (+0.46) (-0.92) Isolated water molecule (gas phase) H-bonded water molecules (liquid or solid phase)
Background image of page 8
Figure 16.4 Boiling Points are High in H-bonded liquids Trend Exceptions O, N, F small sizes and large electronegativities: strong H-bonds
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Drawing Hydrogen bonds between Molecules Problem: In which of the following molecules does hydrogen bonding occur? Draw the hydrogen bonds where appropriate in the molecules.
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 45

Ch16_Part 1_complete_071211 - Chapter #16 Liquids and...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online