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Ch. 1 - Matter I. States of Matter » Kinetic Molecular Theory » States of Matter B. Five States of Matter » Bose-Einstein Condensate » Atoms mount on top of each other A. Kinetic Molecular Theory » KMT » Particles of matter are always in motion. » The kinetic energy (speed) of these particles increases as temperature increases. B. Five States of Matter » Solids » very low KE - particles vibrate but can’t move around » fixed shape » fixed volume 1 B. Five States of Matter » Liquids » low KE - particles can move around but are still close together » variable shape » fixed volume B. Five States of Matter » Plasma » very high KE - particles collide with enough energy to break into charged particles (+/-) » gas-like, variable shape & volume » stars, fluorescent light bulbs, CRTs B. Five States of Matter » Gases » high KE - particles can separate and move throughout container » variable shape » variable volume Ch. 1 - Matter II. Classification of Matter » Matter Flowchart » Pure Substances » Mixtures 2 A. Matter Flowchart A. Matter Flowchart MATTER yes Is the composition uniform? Homogeneous Mixture (solution) PURE SUBSTANCE no Heterogeneous Mixture Colloids no Can it be physically separated? MIXTURE yes » Examples: yes Can it be chemically decomposed? Compound no » graphite element » pepper hetero. mixture » sugar (sucrose) compound » paint » soda hetero. mixture solution Element Suspensions B. Pure Substances » Element » composed of identical atoms » EX: copper wire, aluminum foil B. Pure Substances » Compound » composed of 2 or more elements in a fixed ratio » properties differ from those of individual elements » EX: table salt (NaCl) » Ionic vs Molecular compounds 3 B. Pure Substances » Law of Definite Composition B. Pure Substances » For example… » A given compound always contains the same, fixed ratio of elements. » Law of Multiple Proportions » Elements can combine in different ratios to form different compounds. C. Mixtures » Variable combination of 2 or more pure substances. » Can be separated by physical means. » Distillation, density, filtration, magnetism, boiling points Homogeneous Heterogeneous Two different compounds, each has a definite composition. C. Mixtures » Solution » homogeneous » very small particles » no Tyndall effect Tyndall Effect particles don’t settle EX: rubbing alcohol 4 C. Mixtures » Colloid » heterogeneous » medium-sized particles » Tyndall effect » particles don’t settle » EX: milk C. Mixtures » Examples: C. Mixtures » Suspension » heterogeneous » large particles » Tyndall effect » particles settle » EX: fresh-squeezed lemonade Ch. 1 - Matter » mayonnaise colloid » muddy water suspension » fog colloid » Extensive vs. Intensive solution » Physical vs. Chemical » saltwater » Italian salad dressing III. Properties & Changes in Matter suspension 5 A. Extensive vs. Intensive » Extensive Property » depends on the amount of matter present » Intensive Property » depends on the identity of substance, not the amount B. Physical vs. Chemical » Physical Property » can be observed without changing the identity of the substance » Chemical Property » describes the ability of a substance to undergo changes in identity A. Extensive vs. Intensive » Examples: » boiling point intensive » volume extensive » mass extensive » density intensive » conductivity intensive B. Physical vs. Chemical » Examples: » melting point physical » flammable chemical » density physical » magnetic physical » tarnishes in air chemical 6 B. Physical vs. Chemical » Physical Change » changes the form of a substance without changing its identity » properties remain the same B. Physical vs. Chemical » Signs of a Chemical Change » change in color or odor » formation of a gas » formation of a precipitate (solid) » Chemical Change » changes the identity of a substance » change in light or heat » products have different properties B. Physical vs. Chemical » Examples: » rusting iron chemical » dissolving in water physical » burning a log chemical » melting ice physical » grinding spices physical Intro to periodic table » Groups (Families) » Periods » Noble Gases » Metals vs. Nonmetals » Metalloids (B, Si, Ge, As, Sb, Te) » Alkali Metals » Halogens 7 Changes in States of Matter Changes in States of Matter When we heat a substance, kinetic energy of the particles speed up When a substance changes state, kinetic energy remains constant. The added energy is used to break attractions between particles Heating Curve for Water Temperature (oC) vaporization D 100 melting 0 C E gas condensation liquid B A solid freezing Heat added LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 487 8 How would we separate tap water into its components? Separating mixtures mixture's components have different properties devise a process that selects components with certain properties density, melting point, boiling point, solubility, reactivity, magnetism, polarity filtration: select components by particle size floatation: select components by density crystallization: select components by solubility extraction: select components by solubility distillation: select components by boiling point chromatography: select components by affinity for a 'stationary phase' 9 Separating by physical means » All mixture can be separated by physical means » Remember boiling, melting, freezing, sublimation, condensation, deposition, dissolving are physical changes that can be used to separate mixtures. What occurs when something dissolves? http://www.mhhe.com/physsci/ chemistry/essentialchemistry/flash/ molvie1.swf 10 Solutions » Solute – is the substance being dissolved » Solvent – is the substance doing the dissolving » Solution is the mixture of solute and solvent Factors that affect solubility » Polarity- an uneven distribution of charge » Non polar solvent and polar solute » Solute will not dissolve » Ex/ table salt and olive oil » Polar solvent and polar solute » Solute will dissolve » Ex/ table salt and water » Particle size Solutions » Can vary in concentration » How much solute is dissolved in how much solvent » Expressed as Molarity » Molarity = moles/Liter 11
