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Ch01
- 1. Chapter 1 An Introduction to Chemistry The spectacular colors of the aurora borealis are the result of chemistry in our atmosphere. Foundations of College Chemistry, 13e John Wiley & Sons, Inc Morris Hein and Susan Arena
- 2. Chapter Outline 1.1 WhyStudy Chemistry? 1.5 The Scientific Method 1.2 The Nature of Chemistry 1.6 The Particulate Nature of 1.3 Thinking Like a Chemist Matter 1.4 A Scientific Approach to 1.7 Physical States of Matter Problem Solving 1.8 Classifying Matter Copyright 2011 John Wiley & Sons, Inc 1-2
- 3. The Nature ofChemistry Chemistry is the science dealing with the composition of matter and the changes in composition that matter undergoes. Chemistry is also concerned with energy and energy changes of matter. Copyright 2011 John Wiley & Sons, Inc 1-3
- 4. Thinking Like aChemist Figure 1.1 Inside a drop of lake water we find water molecules, dissolved substances and algae cells. Copyright 2011 John Wiley & Sons, Inc 1-4
- 5. A Scientific Approachto Problem Solving • Define the problem. • Propose possible solutions. – Science refers to this as making an hypothesis. • Decide which way to proceed or solve the problem. – Scientists perform an experiment. Copyright 2011 John Wiley & Sons, Inc 1-5
- 6. The Scientific Method 1.Collect the facts or data relevant to the problem. – Done with carefully designed observations and experimentation. 2. Formulate a hypothesis that accounts for the data and that can be tested further. 3. Plan and do additional experiments to test the hypothesis. 4. Modify the hypothesis as necessary. Copyright 2011 John Wiley & Sons, Inc 1-6
- 7. Your Turn! A clearcolorless liquid is combined with a second clear colorless liquid and the mixture is observed. Which of 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 2011 John Wiley & Sons, Inc 1-7
- 8. 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 2011 John Wiley & Sons, Inc 1-8
- 9. Your Turn! Which ofthese 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 2011 John Wiley & Sons, Inc 1-9
- 10. Your Turn! The statement,“An atom consists of a dense nucleus surrounded by a cloud of electrons”, is an example of a. a theory b. a law c. an hypothesis d. an observation Copyright 2011 John Wiley & Sons, Inc 1-10
- 11. The Particulate Natureof Matter • Matter is anything that has mass and occupies space. • Matter is composed of discrete, tiny, fundamental particles called atoms. The surface of a penny is made up of tiny identical copper atoms packed tightly together. Copyright 2011 John Wiley & Sons, Inc 1-11
- 12. Physical States ofMatter How are they the same? How are they different? Copyright 2011 John Wiley & Sons, Inc 1-12
- 13. Solids • Crystalline solidshave regular, repeating three dimensional patterns. • This is a large crystal of table salt. Copyright 2011 John Wiley & Sons, Inc 1-13
- 14. Solids • Definite shape • Definite volume • Essentially incompressible • Particles are tightly packed together • Particles are held together by very strong forces of attraction Copyright 2011 John Wiley & Sons, Inc 1-14
- 15. Solids • Crystalline solids exist in regular, repeating, three- dimensional geometric patterns. • Amorphous solids do not have any regular, internal geometric pattern. Copyright 2011 John Wiley & Sons, Inc 1-15
- 16. Liquids • Indefinite shape •Definite volume • Only slightly compressible • Particles are mobile, able to move around each other • Particles are held together by strong forces of attraction Copyright 2011 John Wiley & Sons, Inc 1-16
- 17. Gases • Indefinite shape •Indefinite volume • Compressible • Particles are far apart and are small compared to the volume they occupy • The attractive forces are so weak that the particles are independent of each other Copyright 2011 John Wiley & Sons, Inc 1-17
- 18. Solid StatesLiquid of Matter Gas Definite shape Indefinite shape Indefinite shape (Takes shape of (Takes shape of container) container) Definite volume Definite volume Indefinite (Expands to fill the container) Incompressible Slightly Compressible compressible Strong attractive Weaker attractive Energy of particles forces, so particles forces so particles are greater than are locked in place can move around their attractive freely forces Rigidly clinging; Mobile; adhering Independent of each tightly packed other and far apart Copyright 2011 John Wiley & Sons, Inc 1-18
- 19. Your Turn! Which formof water has a definite volume, but no definite shape? a. Ice b. Liquid water c. Steam Copyright 2011 John Wiley & Sons, Inc 1-19
- 20. Your Turn! Which formof water has molecules that are held together tightly by very strong intermolecular forces? a. Ice b. Liquid water c. Steam Copyright 2011 John Wiley & Sons, Inc 1-20
- 21. Your Turn! Which formof water is compressible? a. Ice b. Liquid water c. Steam Copyright 2011 John Wiley & Sons, Inc 1-21
- 22. Your Turn! What physicalstate is found in the container? a. Solid b. Liquid c. Gas Copyright 2009 John Wiley & Sons, Inc 2011 1-22 22
- 23. Your Turn! What physicalstate is found in the container? a. Solid b. Liquid c. Gas Copyright 2009 John Wiley & Sons, Inc 2011 1-23 23
- 24. Classifying Matter • Asubstance has a definite, fixed composition – Element (Na, Cl2, Al) – Compound (NaCl, H2O, CO2) – also called pure substance Copyright 2011 John Wiley & Sons, Inc 1-24
- 25. Your Turn! Which ofthese is not a pure substance? a. Fe b. Fe2O3 c. Fe and O2 d. All of these are pure substances Copyright 2011 John Wiley & Sons, Inc 1-25
- 26. Classifying Matter • Amixture has a composition that can be varied – Solutions are mixtures – Strong coffee versus weak coffee – 5% salt solutions versus 10% salt solutions Copyright 2011 John Wiley & Sons, Inc 1-26
- 27. Classifying Matter Homogeneous matteris uniform in appearance and has the same properties throughout. Examples: Pure substance: Water Mixture: Sugar and water Solutions are always homogeneous 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 2011 John Wiley & Sons, Inc 1-27
- 28. Your Turn! Which ofthese is an example of a solution? a. Oil and vinegar salad dressing b. Iced tea c. Lemonade d. Iced water Copyright 2011 John Wiley & Sons, Inc 1-28
- 29. Classifying Matter Heterogeneous matterconsists 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 gaseous Examples: bromine Pure Substance: liquid and gaseous bromine; iced water Mixture: Iced tea Copyright 2011 John Wiley & Sons, Inc 1-29
- 30. Classifying Matter Copyright 2011 John Wiley & Sons, Inc 1-30
- 31. Your Turn! Freshly openedCoke is an example of a a. An element b. A compound c. A homogeneous mixture d. A heterogeneous mixture Copyright 2011 John Wiley & Sons, Inc 1-31
- 32. Your Turn! Air isan example of a a. An element b. A compound c. A homogeneous mixture d. heterogeneous mixture Copyright 2011 John Wiley & Sons, Inc 1-32
- 33. Distinguishing Mixtures from Pure Substances Mixtures can be separated by physical means. (a) When iron and sulfur exist as pure substances, only the iron is attracted to a magnet. (b) A mixture of Fe and S can be separated by using the difference in magnetic attraction. Copyright 2011 John Wiley & Sons, Inc 1-33
- 34. Your Turn! A clear,colorless liquid is heat in a beaker until all of the liquid is gone. The walls of the beaker are coated with a white crystalline solid. The liquid was: a. An element b. A compound c. A homogeneous mixture d. A heterogeneous mixture Copyright 2011 John Wiley & Sons, Inc 1-34