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Ch. 2 - Matter Properties & Changes in Matter Extensive vs. Intensive Physical vs. Chemical
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A. Extensive vs. Intensive Extensive Property depends on the amount of matter present Intensive Property depends on the identity of substance, not the amount
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A. Extensive vs. Intensive Examples: boiling point volume mass density conductivity intensive extensive intensive
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B. Physical vs. Chemical Physical Property can be observed without changing the identity of the substance Chemical Property Chemical Property describes the ability of a substance to undergo changes in identity
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B. Physical vs. Chemical Examples: melting point flammable density magnetic tarnishes in air physical chemical physical chemical
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B. Physical vs. Chemical Physical Change changes the form of a substance without changing its identity properties remain the same Chemical Change changes the identity of a substance products have different properties
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B. Physical vs. Chemical Signs of a Chemical Change change in color or odor formation of a gas formation of a precipitate (solid) change in light or heat
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B. Physical vs. Chemical Examples: rusting iron dissolving in water burning a log melting ice grinding spices chemical physical chemical physical
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C. Matter Law of Conservation of Matter Antoine Lavoisier (1700’s) Like energy, matter is neither created or destroyed in any process –For example, a burning candle burning fire wood (products are gases and ashes) – mass before = mass after
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C. Matter Law of Definite Composition A given compound always contains the same, fixed ratio of elements. H 2 O is not H 2 O 2 Law of Multiple Proportions Elements can combine in different ratios to form different compounds. Chem/phys HO
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A. Matter Flowchart MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions
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B. Pure Substances Element composed of identical atoms can’t be separated by physical or chemical means EX: copper wire, aluminum foil
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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) Water ( H 2 O)
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C. Mixtures Solution homogeneous very small particles no Tyndall effect Tyndall Effect particles don’t settle EX: rubbing alcohol sugar water
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C. Mixtures Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle EX: milk
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C. Mixtures Suspension heterogeneous large particles Tyndall effect particles settle EX:fresh-squeezed lemonade
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D. Examples Examples: graphite pepper sugar (sucrose) paint soda element hetero. mixture compound Suspension (hetero) Solution (homog.)
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D. Examples of Mixtures Examples: mayonnaise muddy water fog saltwater Italian salad dressing colloid suspension colloid solution suspension
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Define and Explain these methods of Separation in your notes - Filtration – Magnetism – Crystallization – Chromatography – Distillation – Electrolysis- Decanting- Centrifuge- Evaporation-
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A. Energy Energy – the capacity to do work or produce heat. Work is the capacity to move an object over a distance against a force; For example: it moves cars, bakes a cake, keeps ice frozen, lights houses, etc. Two Kinds: Kinetic – energy of motion (waves, molecules, objects) Potential – stored energy or energy of position in the chemical bonds
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A. Energy Forms of energy: 1.Kinetic energy: Electrical Radiant Thermal Motion Sound 2. Potential energy Chemical Stored mechanical Nuclear Gravitational
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A. Energy Law of Conservation of Energy: energy is neither created nor destroyed When we use energy, it doesn’t disappear It can be changed from one form to another: 1).A car burns gasoline, converting the chemical energy into mechanical energy 2). Solar cells change radiant energy into electrical energy
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B Temperature Heat or thermal energy, is the total random kinetic energy of the particles. Heat flows from a hot object to a cold object. For example: can of soda Temperature – measure of the average random kinetic energy of the particles. Temperature – measure of the average random kinetic energy of the particles.
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B Temperature SI unit of temp: Kelvin (K) The zero point on the Kelvin scale is called absolute zero (the point at which the motion of particles ceases). 0 K = -273.15 o C ( no degree symbol and no negative numbers on the Kelvin scale because there is no negative motion! )
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B Temperature Formulas: o C = K – 273 or K = o C + 273 Examples: 1.Antifreeze boils at 197 o C. Convert to Kelvin. 2.Normal body temp is 310 K. Convert to Celsius. 1. 470 K 2. 37 o C
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C Energy Units SI unit of energy: joule (J) calorie (cal) : another unit of energy 1 cal = amount of heat needed to raise the temperature of 1g of water, 1 o C.
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C Energy Units 1 cal does not equal 1 Cal ! Calorie (capital C) is the energy stored in food! 1 Cal = 1000 cal So 200 Cal supplies 200,000 cal of energy! Conversion factors: 1 cal = 4.184 J 1 Cal = 4.184 KJ
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C Energy Units Using dimensional analysis: 3. Convert 540 cal to KJ
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D Metric prefixes 4. Convert 598 g to pg. 5. Convert 598 pg to Gg.
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