Chapter 14 and 15Standard 2 Chemical

Bondingc. Students know that salt crystals are held together by repeating patterns of positive and negative ions held together by electrostatic attraction.

d: Students know the atoms and molecules in liquids move in a random pattern relative to one

another because the intermolecular forces are too weak to hold the atoms or molecules in a solid

form.

I. Physical Properties of the states of matter

Property Gas Liquid Solid

Compressibility

Density

Volume

Shape

Diffusion

Volume when heated

Yes Slightly No

Lowest Moderate

High

Fills container

Definite Definite

of container of container own shape

Rapid Slow Slow-None

Increase Decrease Decrease

Compressibility of gases and

liquids

Compressibility of a solid

Ice in water Ice in alcohol

Liquids and Gases take the shape of container

The molecules in a solid, though they vibrate, do not move very far. When they

wiggle, they wiggle in place. They fit closely together and

keep their position.

Liquids behave this way because in a liquid, the molecules are moving around more than the

molecules in a solid. They slide over each other.

The molecules in a gas are moving around like crazy, bouncing everywhere. They do not

have to stay close to one another

Gases take the shape

of container

What is happening to the volume of a solid when it is heated?

What’s happening to the volume of liquid when heated?

Please define the following terms, they arefound in chapter 14: pages 457-489

1. Intramolecular force

2. Intermolecular force

3. Viscosity

4. Surface Tension

5. Vaporization

6. Condensation

7.Sublimation

8.Deposition

9.Heat of Fusion

10.Heating Curve

What would distinguish among What would distinguish among HH22O O (gas)(gas) HH22O O (liquid)(liquid) HH22OO( solid)( solid)??

steam liquid

ice

Gas Liquid

Solid

Intramolecular Force Intermolecular ForceA. Definition A. Definition

B. Three Types B. Three Types (known as Van Derwaal’s Forces)

C. Example: H2O C. Example: H2O

D. Strength D. Strength

The force of attraction between atoms in the same molecule….BONDING

The force of attraction between an atom of one molecule and its neighboring molecule.

Ionic, Covalent and Metallic Dipole-Dipole, Dispersion & Hydrogen Bonding

Within the same molecule

Intermolecular Force.

The connection between one molecule to another.

Very strong Relatively Weak

To break H-O bond in a water molecule, it takes 463kJ of

energy

To break this force of attraction it takes 6 kJ of energy (for melting)

40.1kJ of energy (for vaporization)

: : --

++

: :

:

:

-

-

-

-

++

+

+

III. Compounds ( ) are HELD by

Metal and Nonmetal Electrostatic Attraction

Stop Day 1

Ionic Bond

Intra v. Inter

Inside Outside

Takes much energy to break! Takes little energy to break!

Intramolecular v. Intermolecular Forces

“Hand-Holding from one Molecule to another

1. Hydrochloric Acid

+_ +

_+

_

Opposite charges attract!!

1. Dipole-Dipole Attraction between opposite charges of neighboring

dipoles.

Dipole-Dipole (a type of intermolecular force )

Draw three molecules of HCl

Covalent Bond

(Intramolecuar)

IV. Types of Intermolecular forces:

Hydrogen Sulfide

• Draw 3 molecules of H2S.

_

++

++ + +

_ _

:

::

:

: :

2. Dispersion

Temporarily creating a dipole by inducing conditions (sufficientlyincreasing pressure and dereasing the temperature): examples: Noblegases/gases

Electrons are not equally distributed at one instant which gives a small instantaneous dipole and the atom or molecule

itself becomes a small dipole.

Helium

Neon condensing

O

H

+H

+

•• ••-

O

H

+H

+

•• ••-

O

H

+H

+

•• ••-

O

H

+H

+

•• ••-

O

H

+H

+

•• ••-

O

H

+H

+

•• ••-

3. HYDROGEN “BONDING”: When Hydrogen is linked to :

Do you remember how much it takes

to melt?

Do you remember how much it takes

to break?

Fluorine, Oxygen or NitrogenThis stuff is FON!!!!

463kJ 6kJ to melt

evaporate?

40.1kJ to evaporate

b. Ammonia

: : :

Hydrogen bonding

H with N

Video on states of matter..\Streaming Video Files\Gases__Liquids__and_Solids

20 min.asx

Start at 8:35

Heating Curve

Time

Solid

Liqui

d

Gas

MeltingFreezing

EvaporationCondensat

ion

Sublimat

ion

Deposition

Melting is also known as Heat of fusion

0

100

oC

sec, min, hr,

Endothermic

Exothermic

Some Properties of LIQUIDSSome Properties of LIQUIDS

Thickness of a liquid: liquid’s resistance to flow.1. Viscosity:

Due to strong intermolecular forces holding molecules together

Viscosity decreases with increasing temperature

2.Surface Tension•A thin membrane made of water molecules on the surface of water.

Water Video