NWTC General Chemistry Ch 01

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NWTC General Chemistry Ch 01 by Steve Sinclair

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  • 1. Chapter 1An Introduction to ChemistryThespectacularcolors of theauroraborealis arethe result ofchemistry inouratmosphere.Introduction to General, Organic, and Biochemistry 10eJohn Wiley & Sons, Inc Morris Hein, Scott Pattison, and Susan Arena

2. Chapter Outline1.1 Why Study Chemistry?1.5 The Scientific Method1.2 The Nature of Chemistry 1.6 The Particulate Nature of1.3 Thinking Like a Chemist Matter1.4 A Scientific Approach to1.7 Physical States of MatterProblem Solving 1.8 Classifying Matter Copyright 2012 John Wiley & Sons, Inc1-2 3. Why study Chemistry? 4. The Nature of ChemistryChemistry is .Copyright 2012 John Wiley & Sons, Inc 1-4 5. The Nature of ChemistryChemistry is the science dealing with the compositionof matter and the changes in composition that matterundergoes.Chemistry is also concerned with energy and energychanges of matter. Copyright 2012 John Wiley & Sons, Inc 1-5 6. Thinking Like a ChemistFigure 1.1 Inside a drop of lake waterwe find water molecules, dissolvedsubstances and algae cells. Copyright 2012 John Wiley & Sons, Inc 1-6 7. A Scientific Approach to Problem Solving Define the problem. Propose possible solutions. Science refers to this as making an hypothesis. Decide which way to proceed or solve theproblem. Scientists perform an experiment.Copyright 2012 John Wiley & Sons, Inc 1-7 8. The Scientific Method1. .2. .3. .4. .Copyright 2012 John Wiley & Sons, Inc 1-8 9. The Scientific Method1. Collect the facts or data relevant to the problem. Done with carefully designed observations andexperimentation.2. Formulate a hypothesis that accounts for the dataand that can be tested further.3. Plan and do additional experiments to test thehypothesis.4. Modify the hypothesis as necessary. Copyright 2012 John Wiley & Sons, Inc 1-9 10. Your Turn!A clear colorless liquid is combined with a second clearcolorless liquid and the mixture is observed. Whichof these is not an observation?a. The test tube became hot.b. The reaction is exothermic.c. The mixture is cloudy.d. The mixture is white. Copyright 2012 John Wiley & Sons, Inc 1-10 11. The Scientific Method Law: Statements of natural phenomena to which there are no known exceptions. Hypothesis: A tentative explanation of the facts that can be tested further Theory: Well-tested hypothesis. Copyright 2012 John Wiley & Sons, Inc1-11 12. Your Turn!Which of these is a law?a. Atoms consist of protons, neutrons, and electrons.b. All matter is composed of atoms.c. Atoms can form chemical bonds by sharing electrons.d. The volume of a gas increases with increasing temperature. Copyright 2012 John Wiley & Sons, Inc 1-13 13. Your Turn!The statement, An atom consists of a dense nucleussurrounded by a cloud of electrons, is an example ofa. a theoryb. a lawc. an hypothesisd. an observation Copyright 2012 John Wiley & Sons, Inc 1-14 14. The Particulate Nature of Matter Matter is anything that has mass and occupies space. Matter is composed of discrete, tiny, fundamentalparticles called atoms.The surface of a penny is made up of tiny identical copper atomspacked tightly together.Copyright 2012 John Wiley & Sons, Inc 1-15 15. Physical States of MatterWhat are they? Copyright 2012 John Wiley & Sons, Inc 1-16 16. Physical States of MatterHow are they the same? How are they different?Copyright 2012 John Wiley & Sons, Inc 1-17 17. Solids Crystalline solids have regular, repeating threedimensional patterns. This is a large crystal of table salt.Copyright 2012 John Wiley & Sons, Inc 1-18 18. Solids Definite shape Definite volume Essentially incompressible Particles are tightly packed together Particles are held together by verystrong forces of attraction Copyright 2012 John Wiley & Sons, Inc 1-19 19. Solids Crystalline solidsexist in regular,repeating, three-dimensional geometricpatterns. Amorphous solids donot have any regular,internal geometricpattern. Copyright 2012 John Wiley & Sons, Inc 1-20 20. Liquids Indefinite shape Definite volume Only slightly compressible Particles are mobile, able to movearound each other Particles are held together by strongforces of attraction Copyright 2012 John Wiley & Sons, Inc 1-21 21. Gases Indefinite shape Indefinite volume Compressible Particles are far apart and are smallcompared to the volume they occupy The attractive forces are so weak thatthe particles are independent of eachother Copyright 2012 John Wiley & Sons, Inc 1-22 22. SolidStatesLiquid of Matter GasDefinite shape Indefinite shapeIndefinite shape (Takes shape of (Takes shape of container)container)Definite volumeDefinite volume Indefinite (Expands to fill the container)Incompressible SlightlyCompressible compressibleStrong attractiveWeaker attractive Energy of particlesforces, so particles forces so particles are greater thanare locked in placecan move around their attractive freelyforcesRigidly clinging;Mobile; adheringIndependent of eachtightly packed other and far apart Copyright 2012 John Wiley & Sons, Inc1-23 23. Your Turn!Make these States of Matter.1. Ice2. Liquid water3. Steam Copyright 2012 John Wiley & Sons, Inc 1-24 24. Classifying Matter A substance isCopyright 2012 John Wiley & Sons, Inc 1-29 25. Classifying Matter A substance has a definite, fixed composition Element (Na, Cl2, Al) Compound (NaCl, H2O, CO2) also called pure substance Copyright 2012 John Wiley & Sons, Inc 1-30 26. Your Turn!Which of these is not a pure substance?a. Feb. Fe2O3c. Fe and O2d. All of these are pure substances Copyright 2012 John Wiley & Sons, Inc 1-31 27. Classifying Matter A mixture has a composition that can be varied Solutions are mixtures Strong coffee versus weak coffee 5% salt solutions versus 10% salt solutionsCopyright 2012 John Wiley & Sons, Inc 1-32 28. Classifying MatterHomogeneous matter is uniform in appearance and hasthe same properties throughout.Examples:Pure substance: WaterMixture: Sugar and water Solutions are alwayshomogeneous mixtures(a) water is the liquid in the beaker, and the white solid in the spoon is sugar.(b) Sugar can be dissolved in the water to produce a solution.Copyright 2012 John Wiley & Sons, Inc 1-33 29. Your Turn!Which of these is an example of a solution?a. Oil and vinegar salad dressingb. Iced teac. Lemonaded. Iced water Copyright 2012 John Wiley & Sons, Inc 1-34 30. Classifying MatterHeterogeneous matter consists of two or more physically distinct phases. A phase is a homogeneous part of a system separated from other parts by physical boundaries.Liquid and gaseousExamples: brominePure Substance: liquid and gaseous bromine; iced waterMixture: Iced teaCopyright 2012 John Wiley & Sons, Inc 1-35 31. Classifying Matter Copyright 2012 John Wiley & Sons, Inc 1-36 32. Your Turn!Freshly opened soda is an example of aa. An elementb. A compoundc. A homogeneous mixtured. A heterogeneous mixture Copyright 2012 John Wiley & Sons, Inc 1-37 33. Your Turn!Air is an example of aa. An elementb. A compoundc. A homogeneous mixtured. A heterogeneous mixture Copyright 2012 John Wiley & Sons, Inc 1-38 34. Homogeneous 35. Distinguishing Mixtures from Pure SubstancesMixtures can be separated by physical means.(a) When iron and sulfur exist as pure substances, only the iron isattracted to a magnet.(b) A mixture of Fe and S can be separated by using the differencein magnetic attraction.Copyright 2012 John Wiley & Sons, Inc1-40 36. Your Turn!A clear, colorless liquid is heat in a beaker until all ofthe liquid is gone. The walls of the beaker are coatedwith a white crystalline solid. The liquid was:a. An elementb. A compoundc. A homogeneous mixtured. A heterogeneous mixtureCopyright 2012 John Wiley & Sons, Inc 1-41 37. Review Questions Do 1, 3, 5, 7, 9 Practice later 2-16 even Copyright 2012 John Wiley & Sons, Inc 1-42