Physical Property Describes form or behavior of matter

Physical Properties ColorColor LusterLuster MalleabilityMalleability ConductivityConductivity HardnessHardness CleavageCleavage Phase at room temp.Phase at room temp. Vapor pressureVapor pressure Melting point Boiling point Heat of fusion Heat of vaporization Density Specific Heat Capacity Physical constants!

Chemical Property Describes how matter interacts with other matter: reactivity

Chemical Change Identity Change

Examples of Chemical Change Synthesis, Decomposition, Single Replacement, Double Replacement, Combustion, Polymerization, Esterification, etc.

Monatomic One-atom Molecule

1 uppercase letter in formula Element

2 or more uppercase letters in formula Compound

Physical Change Identity stays the same

H 2 O(l)  H 2 O(g) Phase changes are physical changes. Identity stays the same.

2H 2 O(l)  2H 2 + O 2 (g) Identity changes. Chemical change.

Diatomic 2-Atom Molecule

Gases Take the shape & volume of their container

Physical Constant Physical property expressed with a # & unit. Independent of sample size.

Liquids Definite volume but no definite shape

Solids Definite volume & definite shape

Compound 2 or more elements chemically combined

Element Cannot be broken down into anything simpler by ordinary chemical or physical methods

Mixture Physical combination of 2 or more pure substances.

Pure Substances Elements & Compounds

Mixtures Heterogeneous or Homogeneous

Distillation Physical method of separating mixture of 2 or more liquids based on differences in boiling points.

Solution Homogeneous Mixture. Liquid & gas phase solutions transmit light. Look translucent. Do not separate on standing.

Suspension Heterogeneous Mixture. Scatter light. Look cloudy. Need to be shaken or stirred. Separate on standing.

NaCl(aq) Homogeneous Mixture. NaCl dissolved in water.

NaCl(s) Pure substance. NaCl in the solid phase.

Variable Composition Mixture

NaCl(l) Pure substance. NaCl in the liquid phase.

NaCl(g) Pure substance. NaCl in the gas phase.

Homogeneous Uniform, constant, the same throughout.

Heterogeneous Non-uniform composition. May see regions that look different. May be more than 1 phase present.

Always Homogeneous Pure substance: Element or Compound

Filtration Physical separation technique used to separate heterogeneous mixtures. Based on differences in particle size.

Sorting Physical separation technique used to separate heterogeneous mixtures. Based on differences in appearance.

Definite & Unique Properties Pure substance. Element or Compound.

Broken into components by chemical decomposition reaction Compound

Definite Composition Pure substance. Element or Compound.

Separated by physical technique Mixture

Triatomic 3-atom Molecule

May be homogeneous or heterogeneous Mixture

Density, melting point, boiling point Examples of physical constants

Law of conservation of matter Mass Before = Mass After

Given: X + 2Y  Q + 3Z Mass Before = Mass After When 44 grams of X react completely with 128 grams of Y, 32 grams of Q are produced. How much Z will be made? The equation is a distractor – 32 = grams Z = 140 g.

No new properties. Properties are a mix of properties of components. Mixture

C 6 H 12 O 6 (s)  C 6 H 12 O 6 (aq) Equation represents dissolving. Dissolving is a physical change.

Physical Properties Used to identify substances.

Atoms can vibrate back & forth about a fixed position. Solid state

Matter Substances ElementsCompounds Mixtures Heterogeneous Mixtures Homogeneous Mixtures Mixtures  Separated by physical methods. Compounds  Separated by chemical methods. Phys. M. Chem. (solutions)(suspensions)

Ways to separate heterogeneous mixtures Sorting Filtration Crystallization Evaporation Distillation Chromatography Differences in density Differences in magnetic properties Differences in solubility

Change of phase terms Evaporation = Freezing = Melting = Condensation = Boiling = Deposition = Fusion = Vaporization = Sublimation = Liquid to gas Liquid to solid Solid to liquid Gas to liquid Gas to solid Solid to gas

Crystallization and Solidification More change of phase terms. Liquid to Solid.

Substances that sublimate CO 2 and I 2

Molecules are relatively far apart from each other & can move from place to place. Gas Phase

One substance dissolved in another substance Solution

Phase at room temperatrue Physical property

Molecules are pretty close, but have enough room to slide or tumble past each other. Liquid Phase

Chromatography Physical separation technique based on differences in intermolecular forces.

Vapor Gas phase of a substance that is usually a liquid at room temperature.

Names for some chemical changes Corrosion, Decomposition, Neutralization, Burning, Fermentation

# of atoms of each element before = # of atoms of each element after Law of Conservation of Matter

Percent Part X 100% Whole

1 upper case letter in formula Element

Cutting, Crumpling, Tearing, Pulling into wire, Hammering into sheet Examples of physical changes

Phase Changes Physical changes

Dissolving Physical Change

Evidence of Chemical Change Production of heat & lightProduction of heat & light Formation of a gas (bubbles)Formation of a gas (bubbles) Formation of a precipitateFormation of a precipitate Change in identifying propertiesChange in identifying properties

Opposite of dissolving. Solid comes out of solution. Precipitation

Particles arranged in a regular geometric pattern. Solid

Potential Energy S L G Endothermic Exothermic

Particle Diagrams                    Pure substance: units the same. molecules of a triatomic compound. Mixture: units differ. monatomic element, diatomic element, triatomic compound.   

Mixture Pure Substance

Compounds vs. Mixtures Always homogeneousMay be homogeneous or heterogeneous Definite compositionVariable composition Definite & unique properties No unique properties Separated into elements by chemical reaction Separated into components by physical methods