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Chemistry I. Matter. Matter. Anything which has mass and takes up space . Law of Conservation of Mass Mass can neither be created or destroyed. Mass must be conserved. Reactants Products 16 g Methane reacts with 64 g of Oxygen to produce 44 g of carbon dioxide and 36 g of water.
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Chemistry I Matter
Matter • Anything which has mass and takes up space. • Law of Conservation of Mass • Mass can neither be created or destroyed. Mass must be conserved. • Reactants Products • 16 g Methane reacts with 64 g of Oxygen to produce 44 g of carbon dioxide and 36 g of water
Solids • Definite Shape • Definite Volume • Rigid, does not flow • Low Kinetic Energy • Cannot be easily compressed • Vibrational Molecular motion
Liquids • Indefinite Shape • Definite Volume • Flows • Medium Kinetic Energy • Considered Non-Compressible • Vibrational and Rotational Molecular Motion
Gas • Indefinite Shape • Indefinite Volume • Flows • High Kinetic Energy • Compressible • Random Chaotic Molecular Motion
Substance • Matter that has a uniform and definite composition. • All substances are either compounds or elements.
gold helium sugar salt How would you describe an element? • Can’t be separated by ordinary chemical or physical means elements What happens when you combine elements? • Can’t be separated without changing the substance. compounds
What do we get when we mix two or more elements or compounds together physically? • Mixture • Contains more than one kind of matter • Can be separated by ordinary physical methods such as: sorting, filtering, solubility, magnetic properties, density, heating, or cooling
coffee brass chicken soup salad dressing 2 kinds of mixtures Homogeneous What kind of mixture?? • Heterogeneous
So… all substances are either elements or compounds and all mixtures are either homogeneous or heterogeneous.S
Chemical Property and Chemical Changes • Chemical Property • The ability of a substance to undergo chemical reactions and to form new substances • Chemical Change • A chemical change results in a change in the chemical composition of the substance involved.
Words That Mean Chemical Change • Burn, rot, rust, decompose, ferment, tarnish, explode, cook, corrode, and biological processes • Evidence of chemical change” • Gas formation (sometimes), temperature change (Exothermic or Endothermic Reaction), change in color or odor, formation of precipitates, formation of light
Physical Properties and Physical Changes • Physical Properties • A quality of a substance that can be observed or measured without changing the substance's chemical properties • Color, odor, density, melting pt. • Physical Change • An alternation of a substance which does not affects its chemical composition.
Physical Change • Examples: • Cutting or breaking an object • Changing state such as: • Solid -> Liquid -> Gas • Melting, Boiling, Freezing
Physical Properties • Luster • Color • Boiling Pt., Freezing Pt, Melting Pt. • Density • Malleable • Brittle • Hard vs. Soft
Baseball and tennis balls have about the same volume. That is, they take up about the same amount of space.
But if you pick them up, you notice a difference. The baseball has more mass.
One property that makes aluminum different from silver is the property of Density
Density is defined as the mass of a substance per unit of volume.
These three blocks have the same volume, Wood Plastic Metal but their masses are different.
M DV Formula for Density Density = Mass/Volume or Mass = Density X Volume or Volume = Mass/Density
Density is a Physical Property • Ratio of the mass on an object to its volume • ρ = mass/volume • Measured in grams/cm3 • 1 mL = 1 cm3 ,therefore, g/ cm3 =1g/mL • Substances with lower densities “float” on objects with higher densities • Ex: Oil floats on water
Specific Gravity • Is the ratio of the density on a substance to the density of water. The density of water is 1 g/cm3. • Example: Since the density of gold is 19.3 g/cm3, then the specific gravity is: • Sp.gr = 19.3 g/cm3 1 g/cm3 Sp. Gr. = 19.3 (No Units!)
A block of aluminum and a block of silver look very similar. Aluminum Silver
The Aluminum and Silver have properties in common and properties that make them different. Property Aluminum Silver Volume 216 cm3 216 cm3 Luster shiny shiny Electrical conductor poor good Heat Conductor good good Phase of matter solid solid Color silver silver Atomic Mass 27 108 Kinds of Atoms Aluminum Silver Atomic Number 13 47 Melting Point 660ºC 962ºC Boiling Point 2467ºC 2162ºC
Intensive vs. Extensive Properties • Intensive Properties DO NOT depend on the amount of matter present • Color, Odor, Malleability, Density, Luster, Temperature, Boiling Point, Melting & Freezing Point • Extensive Properties DO depend on the amount of matter present. • Mass, Weight, Volume, Length
Floating Liquids Which diagram represents the liquid layers in the cylinder? (K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL) 1) 2) 3) K W V V K W W V K
Solution (K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL) 1) V W K
Convert volume to mass PROBLEM: Mercury (Hg) has a density of 13.6 g/cm3. What is the mass of 95 mL of Hg? Note: 1 ml is the same as 1 cm3
Bloody Density If blood has a density of 1.05 g/mL, how many liters of blood are donated if 575 g of blood are given? 1) 0.548 L 2) 1.25 L 3) 1.83 L Caution: The units are liters!
Solution 1) Unit Plan: g mL L 575 g x 1 mL x 1 L = 0.548 L 1.05 g 1000 mL
Light or Heavy Metals You have 3 metal samples. Which one will displace the greatest volume of water? 1 2 3 Discuss your choice with another student. 25 g Al 2.70 g/mL 45 g of gold 19.3 g/mL 75 g of Lead 11.3 g/mL
Solution 1) 25 g Al x 1 mL = 9.2 mL 2.70 g 25 g Al 2.70 g/mL
Chemistry IThurs, Sept 17th, 2009 • Density Lab-Due Today • WebAssign Due Wednesday, Sept 23rd , at 11:59 pm • Science Festival • HW: Matter-Substances vs. Mixtures • HW: Print Out Due on Friday!!! • Lab Tomorrow-Meet Room W215
Chemistry IFri, Sept 18th, 2009 • Check Printout of WebAssign • Conservation of Mass Lab-Due EOC • WebAssign Due Wednesday, Sept 23rd , at 11:59 pm • Science Festival • HW: Complete Conservation of Matter Lab
Chemistry IMon, Sept 21st, 2009 • Daily Quiz • WebAssign Due Wednesday, Sept 23rd , at 11:59 pm • Science Festival • HW: Brings Clothes for Lab Tomorrow
Chemistry ITues, Sept 22nd, 2009 • Collect Element Ball • WebAssign Due Wednesday, Sept 23rd , at 11:59 pm • Science Festival-Sign Up • HW: STUDY FOR QUIZ-TOMORROW
Chemistry IWeds, Sept 23rd , 2009 • Matter Quiz • Notes: Test Review • WS: Review-Due Tomorrow • WebAssign tonight at Wednesday, Sept 23rd , at 11:59 pm • Science Festival-Sign Up • HW: STUDY FOR TEST
Unit 2 Exam - Review Test Format: 25 multiple choice questions - scantron You will need a calculator and a #2 pencil • Density = Mass / Volume • Density Applications • Density layer columns • Ability to sink or float • Density Calculations • Using significant figures • Matter • Anything that has mass and occupies space (know examples) • Mass • Amount of matter in an object • Volume • Amount of space an object occupies • Conservation of Mass • Mass of reactants = mass of products • Calculations • Properties and Changes • Physical Properties (know examples) • Physical Changes (know examples) • Chemical Properties (know examples) • Chemical Changes (know examples) • Definitions and applications • Elements, Compounds, Mixtures • Classify matter (know examples) • Definitions and applications • Homogeneous vs. Heterogeneous mixtures • Classify mixtures (know examples) • Definitions and applications • Endothermic vs. Exothermic reactions • Classify reactions (know examples) • Definitions and applications • Intensive vs. Extensive properties • Classify reactions (know examples) • Definitions and applications Please look over your notes, quizzes, WebAssign, practice worksheets, and labs PPT available on-Line at my faculty web site.
Chemistry IFri, Sept 25th , 2009 • Video: 10 Greatest Discoveries in Chemistry • Make Up Tests • Make Up Quizzes • Science Festival-Sign Up Last Day END OF SIX WEEKS