Slide 1Chemistry and MatterAtoms and MoleculesStudy of ChemistryStates of MatterClassification of MatterElementsCompoundsMixturesElements, Compounds, and MixturesHomogeneous Mixtures and Heterogeneous MixturesClassification of MatterClassification of MatterSlide 14Slide 15Types of PropertiesTypes of PropertiesTypes of ChangesSlide 19DistillationFiltrationChromatographySlide 23SI UnitsPrefixes in Metric System and SI UnitsLength and MassVolumeVolume MeasurementsTemperatureDensitySlide 31Slide 32Significant FiguresSignificant FiguresSignificant Figures in CalculationsSignificant Figures in CalculationsDimensional AnalysisDimensional AnalysisSlide 39Slide 40Slide 41Slide 42MatterAndMeasurementChapter 1Introduction:Matter and MeasurementMatterAndMeasurementChemistry and Matter•In chemistry we study composition, structure, and properties of matter and the changes it undergoes.•We define matter as anything that has mass and takes up space.MatterAndMeasurementAtoms and Molecules•Atoms are the building blocks of matter. They are the smallest distinctive units in a sample of matter.•Atoms can combine to form molecules in which two or more atoms are joined together in specific shapes.MatterAndMeasurementStudy of ChemistryStudying chemistry in two levels:•macroscopic level – ordinary-sized objects•microscopic level – atoms and moleculesMatterAndMeasurementStates of MatterMatterAndMeasurementClassification of Matter•A pure substance (or a substance) is matter that has distinct properties and a composition that does not vary from one sample to another.•All substances are either elements or compounds.MatterAndMeasurementElements•Each element is composed of only one kind of atom.–Currently, 118 elements are known.–Each element has a chemical symbol: O, H, Ag, Fe, Cl, Hg, etc.–Elements are listed in the periodic table.MatterAndMeasurementCompounds•A compound is made of two or more elements in fixed proportion, and can be broken down to simpler substances.- water, H2O: 11% H and 89% O by mass- the law of constant composition (or the law of definite proportions)- Compounds can be broken down into more elemental particles.MatterAndMeasurementMixturesMost of the matter consist of mixtures of different substances. •Each substance in a mixture retains its own chemical identity and its own properties. •A mixture does not have a fixed composition.MatterAndMeasurementElements, Compounds, and MixturesMatterAndMeasurementHomogeneous Mixtures and Heterogeneous Mixtures•A homogeneous mixture has the same composition throughout, though the composition of different homogeneous mixtures may vary.–Examples: soda pop, salt water, 14K gold, air, and many plastics –Homogeneous mixtures are called solutions.•A heterogeneous mixture varies in composition and/or properties from one part of the mixture to another.–Examples: adhesive tape, CD, pen, battery, chair, and people CuSO4 solutionGraniteMatterAndMeasurementClassification of Matterwhich exists asSubstancesMixtureswhich may beElements Compounds Heterogeneouswhich may beHomogeneousMatterMatterAndMeasurementClassification of MatterMatterAndMeasurementExample“White gold” contains gold and a ”white” metal, such as palladium. Two samples of white gold differ in the relative amounts of gold and palladium they contain. Both samples are uniform in composition throughout. Classify white gold.ExampleWhich of the following can the composition vary from sample to sample?(a) pure substance(b) element(c) both homogeneous and heterogeneous mixtures(d) Homogeneous mixture(e) Heterogeneous mixtureMatterAndMeasurementProperties and Changes of MatterMatterAndMeasurementTypes of Properties•Physical Properties…–Can be observed without changing a substance into another substance.•Boiling point, density, mass, volume, etc.•Chemical Properties…–Can only be observed when a substance is changed into another substance.•Flammability, corrosiveness, reactivity with acid, etc.MatterAndMeasurementTypes of Properties•Extensive Properties…–Depend upon the amount of the substance present.•Mass, volume, energy, etc.•Intensive Properties…–Are independent of the amount of the substance that is present.•Density, boiling point, color, etc.MatterAndMeasurementTypes of Changes•Physical Changes–These are changes in matter that do not change the composition of a substance.•Changes of state, temperature, volume, etc.•Chemical Changes–Chemical changes result in new substances.•Combustion, oxidation, decomposition, etc.Chemical reactionMatterAndMeasurementSeparation of MixturesMatterAndMeasurementDistillationDistillation uses differences in the boiling points of substances to separate a homogeneous mixture into its components.MatterAndMeasurementFiltrationIn filtration solid substances are separated from liquids and solutions.MatterAndMeasurementChromatographyThis technique separates substances on the basis of differences in solubility in a solvent.•Suggest a method to separate a mixture of sugar and sand.MatterAndMeasurementUnits of MeasurementMatterAndMeasurementSI Units•SI Units - the International System of Units (Système International d’Unités)•A different base unit is used for each quantity.SI Base UnitsMatterAndMeasurementPrefixes in Metric System and SI UnitsPrefixes convert the base units into units that are appropriate for the item being measured.MatterAndMeasurementLength and Mass•Length–The SI base unit of length is the meter.–Other commonly used units: kilometer (km; 1000 m)centimeter (cm; 0.01 m)millimeter (mm; 0.001 m)•Mass–Mass is the quantity of matter in an object; weight is a force.–The SI base unit of mass is the kilogram (kg; 1000 g).–Other commonly used mass units: gram (g) milligram (mg; 0.001 g)MatterAndMeasurementVolume•The derived SI unit of volume if m3.•The most commonly used metric units for volume are the liter (L) and the milliliter (mL).–A liter is a cube 1 dm long on each side.–A milliliter is a cube 1 cm long on each side.MatterAndMeasurementVolume MeasurementsDifferent measuring devices have different uses and different degrees of uncertainty.MatterAndMeasurementTemperatureK = C + 273.15F = 9/5(C) + 32C = 5/9(F − 32)•Temperature is a measure of the average kinetic energy of the particles in a sample.•The Celsius (oC) scale is based on the properties of water.–0C is the freezing point of water.–100C