11.5 – 11.6 Student Notes

B. Intermolecular Forces; Explaining Liquid Properties

1. Intermolecular forces – def –

2. Types of Interactions (van der Waals forces)

a. Def –

b. Dipole-dipole forces –

Polar molecules

Dipole moments

c. London (dispersion) forces

1.

2. Tend to increase with

3. For molecules of about the same molecular weight,

3. Van der Waals Forces and the Properties of Liquids

a. London force is always present and usually dominant

b. Dipole-dipole usually only appreciable in

c. Boiling points

d. Surface tension

e. Viscosity

4. Hydrogen bonding

a. Def –

b. Trends

5. Determining Relative Vapor Pressure on the Basis of Intermolecular Attraction

For each of the following pair, choose the substance you expect to have the lower vapor pressure at a given temperature:

a. carbon dioxide or sulfur dioxide

b. dimethyl ether or ethanol

IV. Solid State

A. Classification of Solids by Type of Attraction of Units

1. Molecular solid

a. Structural units

b. Attractive forces between units

c. Examples

2. Metallic solid

a. Structural units

b. Attractive forces between units

c. Examples

3. Ionic solid

a. Structural units

b. Attractive forces between units

c. Examples

4. Covalent network solid

a. Structural units

b. Attractive forces between units

c. Examples

B. Identifying Types of Solids

Which of the four basic types of solids would you expect the following substances to be?

1. Solid ammonia

2. Cesium

3. Cesium iodide

4. Silicon

C. Physical Properties

1. Melting Point and Structure

2. Hardness and Structure

3. Electrical Conductivity and Structure