PHYSICAL PROPERTIES OF MATTER

Phases of Matter

Phases of Matter

A. Phases of matter = solids (s), liquids (l), gas (g)

B. Phase depends on:1. Temperature

2. Pressure (force)

C. A change in phase is accompanied by:

* an absorption of energy = ENDOTHERMIC

OR* a release of energy =

EXOTHERMIC

D. The phase is characterized by:

* The type of motion of the particles

* The distance between the particles

3 Types of Motion include:

1. vibrational – back and forth motion

2. rotational – spin on axis

3. translational – moves from one positon to

another; travels over a distance

Properties of Solids, Liquids, & Gases

1. SOLIDS: * Particles are aligned in a geometric

pattern* Particles are in a

fixed position* Small distance or

space between particles* Vibrational

movement ONLY* Solids have definite

shape & volume

2. LIQUIDS: * some space between particles

* Particles are NOT aligned in a fixed

position * motion = vibrational

& rotational

particles FLOW or roll over * HAS definite volume * NO definite shape

3. GASES: * Large distance between particles

Particles are spaced far apart!

* contain all 3 types of motion:

Vibrational, Rotational, & Translational

* NO definite shape * NO definite volume

ENTROPY= THE DEGREE OF RANDOMNESS

OR

DISORDER

As energy is absorbed (ENDOTHERMIC)solids liquids

gases

Entropy INCREASES

As Energy is released (EXOTHERMIC):

GAS LIQUID SOLID

Entropy DECREASES

PHASE CHANGE DIAGRAM

• A graph that plots temperature vs. heat at constant rate.

• Heat can be added (Endothermic or Heating Curve)

OR• Heat can be released (Exothermic or

Cooling Curve)

HEATING CURVE – ENDOTHERMICENTROPY INCREASES

COOLING CURVE – EXOTHERMICENTROPY DECREASES

Terms to know:1. Endothermic = heat is absorbed

* Entropy increases* melting = s l* vaporization = l g* sublimation = s g

* Heat of Fusion = heat needed to melt ice (s l)

* Heat of Vaporization = heat needed to vaporize

water to steam ( l g)

Endothermic Phase Changes: ICE to WATER to STEAM

Entropy INCREASES

2. Exothermic = Heat is released* Entropy Decreases* Freezing: l s (solidification)* Condensation: g l

* Heat of solidification = amount of heat needed to be released to change a liquid to a solid

* Heat of condensation = amount of heat needed to be released to change a gas to a liquid

Mathematical Equations:

Q = m x Hf use when melting or freezing

Q = m x Hv use when vaporizing or condensing

REFERENCE TABLE B:Heat of Vaporization = 2260 J/g

Heat of Fusion = 334 J/g