PHYSICAL PROPERTIES 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 – ENDOTHERMIC ENTROPY INCREASES

COOLING CURVE – EXOTHERMIC ENTROPY 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