Physical-Chemical Properties Mixtures/Elements/Cmpds Adapted from Matter, Building Block of the Universe Prentice Hall Made by Jim Barnaby 2004

MatterMatterAnything with mass and volume

Physical PropertiesPhysical PropertiesPhysical Properties describe objects (matter) and are used to identify and compare different types of matter Color, odor, size, shape, state (phase), texture, hardness, taste, density, boiling point, melting point, freezing point, magnetism, conductivity, conducts heat, mass, weight, volume, solubility

Physical ChangePhysical ChangeChange in size, state or shape or changes in other physical properties. One or more physical attributes transform, but the chemical identity is unchanged.

Differentiate gasesSuppose you have to distinguish between two gases, Oxygen and Hydrogen (O2 & H2). Both are colorless, tasteless and odorless. Since they are gases they have no definite volume. Each has a specific density but you cannot determine volume to get density. Describe a brief procedure you can use to differentiate between the two gases (O2 & H2).

Chemical PropertiesChemical PropertiesThe properties that describe how a substance changes into other new substances.The tendency of a substance to change chemical identity (transforms into a different substance)

Chemical property-changeA Chemical Property describes a substances ability to change into a different substance, a Chemical Change is the process by which the substance changes.(Example, the ability of a substance to burn is a chemical property, the process of burning is a chemical change)

Chemical ReactionChemical Change (Chemical Reaction)New substances with different properties are formedA substance changes its chemical identity, atoms are re-arranged to produce a new substance with different propertiesChemical ReactionNew substance is formed by the re-arrangement of atoms

Evidence of Chemical ChangeEvidence of chemical changeColor change, rust, exothermic (hot-produces heat energy), endothermic (cold-absorbs heat energy), light, bubbles, burning, explosion (releases energy), flammabilityability to burn

Physical or Chemical Change?The main difference between a physical and a chemical change is that a chemical change involves the production of a new substance. Physical changes are easily reversed.

Physical or ChemicalPhysical or Chemical changeLight a matchSlice a cake into 4 piecesIce cream melts into mushAlka-seltzer in waterCrumple a piece of Al foilBaking soda and vinegar

Physical or ChemicalWater freezes into iceWater boilsJeans fade in the sunBleach clothesDigest foodA candle meltsList physical properties for clock, table, person, ..etc

DemosLabs Demonstrations:Roast marshmallowsC12H22O11 draw rxn on the boardComplete and turn in metal salts flame labInvestigate aquarium experimentDeep rock jug

Grocery StoreHow is a grocery store (supermarket) set up?Produce, meats, dairy, frozen foods, drinks, etcImagine how hard it would be to find items if there were no organized way of groceries in a grocery store. Frozen pizza next to panty hose

Classification of matterAccording to makeup, matter is classified into (4 classes): Matter exists as:MixturesSolutionsElementsCompounds

MixtureMixtureMatter that consists of two or more substances mixed together but not chemically combined. The substances keep their separate identities and most of their own properties, however their chemical composition does not change.2 types of mixtures are heterogeneous and homogeneous mixtures

Heterogeneous MixtureHeterogeneous mixtureLeast mixed mixture does not appear to be the same throughout. Parts are easy to recognize and separate. Examples: granite, tacos, bowl of cereal, big Mac, Italian salad dressing, concrete, crunchy peanut butter, sandwich.

Homogeneous MixtureHomogeneous mixtureWell-mixed, appears to be the same throughout. Particles are small, not easily recognizable and do not settle when the mixture is allowed to stand. Examples: air, milk, glass, stainless steel, kool aid

ColloidsColloidsHomogeneous mixtures where the particles are mixed together but not dissolved. The particles in a colloid are relatively large in size and are kept permanently suspended. Colloids do separate on standing as do many heterogeneous mixtures.Examples: milk, whipped cream, toothpaste, suntan lotion

SolutionSolutionType of homogeneous mixture formed when one substance is dissolved in another. Best mixed of all mixtures. Particles are evenly spread out. Examples: soda pop, lemonade, kool aid, teaSolute substance that is dissolved Solvent substance that does the dissolving

Properties of solutionsSee chart on word documentSolutions can exist in any of the three phases: solid, liquid or gas.Property of solution is that particles are evenly spread out (dissolved)

SolubilitySolubilityAmount of solute that can be completely dissolved in a given amount of solvent at a specific temperature.How can you increase the solubility of a substance?Increase temp-increase solubility (add heat energy)Increase agitation-increase solubilityDecrease temp-decrease solubility

Soluble/InsolubleA substance that dissolves in another substance is soluble in that substance.(sugar is soluble in water) Insoluble does not dissolve (sand in water)

AlloysAlloysMetal solutionsSolids dissolved in solids.Gold jewelry is a solid solution of Au and CuBrass is an alloy of Cu and ZnSterling silver is an alloy of Ag and CuStainless steel is an alloy Cr and Fe

Pure SubstancesPure substancesMatter that cannot be separated by physical means (elements and compounds)ElementSubstance that contains only 1 type of atomExamples: H, He, O, B anything from periodic table

CompoundsCompoundSubstance formed when different types of atoms bond with one anotherComposed of 2 or more atoms bonded togetherExamples: NaCl, C12H22O11, NaOH, AgCl

Compounds differChemical compounds are uniquely different from the elements that make them up. Sodium and chloride are extremely toxic by themselves, however sodium chloride is necessary for good health.

MoleculeMolecule2 or more atoms bonded together. Smallest particle of a compound that has all the properties of that compound.Examples: H2O NaClSketch molecules on board

Elements, compounds, mixturesSee word document for chartSketch matter flow chart on board (This is on study guide to save copy time)Classify list from word document (do orally)

Separate mixturesExplain how you could use physical properties to separate the following mixtures:Sand-saltOil-waterSalt-waterRubbing alcohol-waterSawdust-sandGold-sandIron filings-sulfur

AtomsAtomSmallest particle of an element that has all the physical and chemical properties of that element Basic building block of all matterAtoms are mostly empty space (analogies)

Chemical SymbolChemical SymbolShorthand way to represent an elementSingle letter or first letter is always capitalizedSecond letter is always lower caseAs, Fe, Se, He, Ar, .

Chemical FormulaElemental (Chemical) formulaCombination of chemical symbols to represent a substances identity Atomic symbol along with a numerical subscript to indicate the number of atoms grouped together

Chemical formulasO2-2 - O atomsO3-3 O atomsS8-8 S atoms4 O2-4 O2 molecules- 8 O atomsNaCl, Fe2O3, KCl

Applied Chemical Formulas List the element and the number of atoms for each elementNaHCO3C12H22O113 H2SO45 CaCO3

RememberRememberchemical compounds are uniquely different from the elements from which they are made.Na+ - toxic explosive in waterCl- - toxic green gas, death in less than 1.5 secondsNaCl table saltsodium chlorideessential for good health

The real worldIn nature, it is rare that elements or compounds are found in a purified state. We find them mixed together in mixtures, which can be separated by differences in physical properties.

Chemical EquationChemical EquationDescription of a chemical reaction using symbols and formulas2 H2 + O22 H2O Draw molecules on board

Chemical ReactionChemical ReactionAtoms are re-arranged and a new substance with different properties is formedReactants ProductsYield, produce

Chemical reactionExisting bonds are broken, atoms are re-arranged, new bonds are formed to produce new substancesEnergy is either absorbed or released

Exothermic ReactionExothermic chemical reaction (HOT)Exo out of thermic heatHeat energy is released

Endothermic ReactionEndothermic chemical reaction (COLD)Endo into thermic heatHeat energy is absorbed(Need to add heat energy to keep reaction going)

CatalystCatalystSpeeds up a chemical reaction without being permanently being changed itself

Law of Conservation of massLaw of Conservation of Mass (Matter)Matter is neither created or destroyed in a chemical reaction. Atoms are re-arranged, however, the same atoms and number of atoms remain on both sides of the reaction.

Balancing equationsBalance chemical equationsWrite equations on boardPrepare for unit quiz