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
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