Introduction to Chemistry and Active Learning - Cengage Learning

Mark S. Cracolice Edward I. Peters www.cengage.com/chemistry/cracolice Chapter 1 Introduction to Chemistry; Introduction to Active Learning Mark S. Cracolice The University of Montana Copyright ©2016 Cengage Learning. All Rights Reserved. Introduct...

Mark S. Cracolice Edward I. Peters www.cengage.com/chemistry/cracolice Chapter 1 Introduction to Chemistry; Introduction to Active Learning Mark S. Cracolice The University of Montana Copyright ©2016 Cengage Learning. All Rights Reserved. Introduction to Chemistry Chemistry - Science that studies how molecules behave Molecules: Smallest unit particle of a pure substance that can exist independently and possess the identity of the substance Chemists ponder on things that make up the universe as molecules Copyright ©2016 Cengage Learning. All Rights Reserved. Antoine Lavoisier (la-vwuh-zay) Father of modern chemistry Author of Traité Élémentaire de Chime Published in 1789, marks the beginning of modern chemistry Conducted experiments and formulated theories Revolutionized thinking that was accepted from the time of the Greeks Copyright ©2016 Cengage Learning. All Rights Reserved. Beginning of Experimental Chemistry Phlogiston theory - All matter that has the ability to burn contains phlogiston In the process of burning wood, phlogiston is lost and ash remains Lavoisier’s phosphorus and mercury burning experiments Contradicted phlogiston theory Resulted in a new hypothesis When substance burns, it combines with oxygen in air https://www.youtube.com/watch?v=55yJPs-_R1w Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.3 - Lavoisier’s Phosphorous Burning Experiment The ash that remains after the phosphorus is burned weighs more than the original phosphorus There is less air in the jar after burning than before Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.4 – Lavoisier’s Apparatus for Investigating the Reaction of Mercury and Oxygen Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Scientific Method Observing Proposing a hypothesis Hypothesis: Tentative explanation for observations Being skeptical Predicting an outcome that should result if the hypothesis is true Testing the prediction by an experiment https://www.youtube.com/watch?v=SMGRe824kak Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Scientific Method Revising or changing the hypothesis Testing the revised or new hypothesis and predicting a new experimental outcome Upgrading the hypothesis to a theory Theory (scientific model): Hypothesis that is tested and confirmed by experiments under varied conditions without contradiction Conducting more experiments Copyright ©2016 Cengage Learning. All Rights Reserved. Scientific Method Communication has led to the growth of scientific knowledge Modern scientists communicate with each other through technical knowledge Law: Summary of a pattern of regularity detected in nature In order to be classified, the law must have no exceptions Copyright ©2016 Cengage Learning. All Rights Reserved. Theory vs Law https://www.youtube.com/watch?v=GyN2RhbhiEU Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.5 - The Scientific Method Copyright ©2016 Cengage Learning. All Rights Reserved. Chemistry Today Chemists study matter and its changes from one substance to another Investigate energy gained or released in chemical changes Holds a central position among the sciences: Research in chemistry overlaps in physics, biology, geology, etc. Industries employ chemists for: Research and product development Quality control and product supervision Sales Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.7 - Chemistry is the Central Science Copyright ©2016 Cengage Learning. All Rights Reserved. Classification of Chemistry Analytical Qualitative and quantitative analysis of a sample of matter Biochemistry Concerned with living systems Organic Study of properties and reactions of compounds that contain carbon Inorganic Study of all substances that are not organic Physical Examines the physics of chemical change Copyright ©2016 Cengage Learning. All Rights Reserved. Learning Chemistry Goal - To gain adequate knowledge in a reasonable amount of time Choices Commit to sufficient time outside of class Commit to quality time when studying Commit to utilizing all learning resources Resources - Lectures, textbook, online learning tools, laboratory, instructor office hours, the Internet, and the library Copyright ©2016 Cengage Learning. All Rights Reserved. Learning Chemistry Commit to improvement Think like a chemist Think conceptually Embrace multiple ways of knowing Develop thinking skills Utilize feedback in a positive manner Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.11 - How to Think Like a Chemist Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 1.12 - The Feedback Loop Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Section-by-Section Goals Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Learn It Now! Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Active Examples Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Target Checks Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook P/Review Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Thinking About Your Thinking Copyright ©2016 Cengage Learning. All Rights Reserved. Features of the Textbook Key terms Frequently asked questions Concept-linking exercises Small-group discussion questions End-of-chapter questions, exercises, and problems Appendices Appendix I: Chemical calculations Appendix II: The SI system of units Glossary Copyright ©2016 Cengage Learning. All Rights Reserved. Choice Reader can choose to: Continue learning as before Improve the learning skills The chapter provides suggestions to: Improve learning skills Upgrade study habits Copyright ©2016 Cengage Learning. All Rights Reserved. True or false? An Important part of the Scientific method is reviewing the work of other scientists. Copyright ©2016 Cengage Learning. All Rights Reserved. True or False? When planning a new experiment, it is unethical to look at the results of experiments reported by others. Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Is this an Observation, Hypothesis, or experiment? A red gummi bear burns vigorously when it is dropped into molten potassium chlorate. Observation Hypothesis Experiment Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Is this an Observation, Hypothesis, or Experiment? Dropping Gummi bears of different colors into molten potassium chlorate Observation Hypothesis Experiment Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Is this an observation, hypothesis, or experiment? If you place a gummi bear outside under the sun, then it shouldn't melt. Observation Hypothesis Experiment Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Is this an Observation, Law, or Theory? In our genetic code, we share a common ancestor with apes. Therefore, evolution is true, and we are derived from apes. Observation Law Theory Copyright ©2016 Cengage Learning. All Rights Reserved.  Mark S. Cracolice Edward I. Peters www.cengage.com/chemistry/cracolice Chapter 2 Matter and Energy Mark S. Cracolice The University of Montana Copyright ©2016 Cengage Learning. All Rights Reserved. Learning Objectives (2.1) Identify and explain the differences between interpreting and describing matter at the macroscopic, microscopic, and particulate levels Define the term model as it is used in chemistry to represent pieces of matter too small to see (2.2) Identify and explain the differences among gases, liquids, and solids in terms of (a) the macroscopic-level properties shape and volume, (b) particle movement; and (c) particle spacing Copyright ©2016 Cengage Learning. All Rights Reserved. Learning Objectives (2.3) Distinguish between physical and chemical properties at both the particulate level and the macroscopic level Distinguish between physical and chemical changes at both the particulate level and the macroscopic level (2.4) Distinguish between a pure substance and a mixture at both the particulate level and the macroscopic level Distinguish between homogenous and heterogeneous matter (2.5) Describe how distillation and filtration rely on physical changes and properties to separate components of mixtures Copyright ©2016 Cengage Learning. All Rights Reserved. Learning Objectives (2.6) Distinguish between elements and compounds Distinguish between elemental symbols and the formulas of chemical compounds Distinguish between atoms and molecules State the Law of Definite (or Constant) Composition, and explain its implication for how compounds and mixtures differ in composition Copyright ©2016 Cengage Learning. All Rights Reserved. Course Learning Objectives CLO 2.1 Discuss the states of matter. CLO 2.2 Describe the chemical and physical properties of matter. CLO 2.3 Differentiate among compounds, elements, and mixtures. Copyright ©2016 Cengage Learning. All Rights Reserved. Matter Everything that has mass is matter Macroscopic: Consideration of matter on a scale observable by the human eye Geologists study matter at this level Microscopic: Consideration of matter on a scale observable with a classic microscope Microbiologists study matter at this level Particulate: Matter on a level too small to be observable with the human eye or microscope Needs to be modeled Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.1 - Macroscopic, Microscopic, and Particulate Matter Copyright ©2016 Cengage Learning. All Rights Reserved. Model A representation of something Chemists use models of atoms and molecules that are based on experimental data Common molecular models Ball-and-stick: Three-dimensional representation of a molecule that uses balls to represent atoms and sticks to represent electron pairs Space-filling: Shows the outer boundaries of the particle in three-dimensional space, uses spheres of different color to represent different atoms Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.2 - Models and Symbols Used to Represent Molecules Copyright ©2016 Cengage Learning. All Rights Reserved. Which type of model is this? acetylene Copyright ©2016 Cengage Learning. All Rights Reserved. Which type of model is this? acetylene Copyright ©2016 Cengage Learning. All Rights Reserved. Model Represented by a chemical symbol Example: H represents a hydrogen atom, O represents an oxygen atom H2O - Chemical formula of water (states that one molecule of water consists of two hydrogen atoms and one oxygen atom) Copyright ©2016 Cengage Learning. All Rights Reserved. States of Matter Differences among solids, liquids, and gases can be explained in terms of kinetic molecular theory Kinetic molecular theory: All matter consists of extremely tiny particles that are in constant motion Kinetic - Motion Molecular comes from molecule Molecules are attracted to one another The speed at which particles move is faster at higher temperatures and slower at lower temperatures Copyright ©2016 Cengage Learning. All Rights Reserved. States of Matter In gas, particles move fast and far apart, overcome attractive forces In liquid, molecules touch one another and move freely among themselves In solid state, molecules vibrate in fixed positions Crystalline solid: Solid in which molecules are arranged in a definite pattern Amorphous solid: Solid which lacks pattern in its particle arrangement Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.5 - Three States of Matter Illustrated by Water Copyright ©2016 Cengage Learning. All Rights Reserved. Properties and Changes Physical properties: Characteristics that can be observed and measured without altering the identity of the substance Physical change: Changes that occur in the form of a substance without changing its chemical identity Chemical change: Chemical identity of a substance is destroyed and a new substance forms (old bonds break; new bonds form) Known as chemical reaction Chemical properties: All chemical changes possible for a substance Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.7 - Physical Change Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.9 - Chemical Changes Copyright ©2016 Cengage Learning. All Rights Reserved. Pure Substances and Mixtures Pure substance: Sample consisting of only one kind of matter Possess a unique set of physical and chemical properties Identity does not change with physical change Mixture: Sample of matter that consists of two or more pure substances that have been mixed together Properties depend on the substances in it Copyright ©2016 Cengage Learning. All Rights Reserved. First guess! Which of these is a mixture or pure substance? Apple juice? Orange juice? Distilled water? Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.12 - Comparison of Boiling Temperatures Pure water has a constant boiling point—a physical property The boiling point of a mixture (solution) changes as the composition of the mixture changes Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.13 - Pure Substances and Mixtures at the Particulate Level A pure substance cannot be distinguished from a mixture of uniform appearance by observation alone at the macroscopic level Copyright ©2016 Cengage Learning. All Rights Reserved. Pure Substances and Mixtures Solution: Homogenous mixture of two or more substances of molecular or ionic particle size Concentration can be varied within certain limits Homogeneous: Having uniform appearance and uniform properties throughout Example: gasoline Phase: Visibly distinct part of a heterogeneous sample of matter Heterogeneous: Having a non-uniform composition with visibly different phases Example: strawberry preserves Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.14 - Homogenous Pure Substances and Homogenous Mixtures Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.15 - Separating a Mixture of Iron and Sulfur Copyright ©2016 Cengage Learning. All Rights Reserved. Separation of Mixtures Methods depend on differing physical properties among components Distillation: Process of separating components of a mixture by boiling off and condensing the more volatile component Relies on physical change Distilled water: Water purified by distillation Filtration: Process of passing a liquid through a filter to separate components of a mixture based on relative particle size Based on physical properties of the components Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.16 - Laboratory Distillation Apparatus Copyright ©2016 Cengage Learning. All Rights Reserved. Distillation Video https://youtu.be/xRGR5ZvO3AU Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.17 - Gravity Filtration Copyright ©2016 Cengage Learning. All Rights Reserved. Filtration Video https://www.youtube.com/watch?v=WSdGxQBnhZU Copyright ©2016 Cengage Learning. All Rights Reserved. Types of Pure Substances Element: Pure substance that cannot be decomposed into other pure substances by ordinary chemical means Possess a unique set of physical and chemical properties Example: Silver Compound: Pure substance that can be broken down into two or more other pure substances by a chemical change Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.19 - Separation of Compounds versus Separation of Mixtures Copyright ©2016 Cengage Learning. All Rights Reserved. Figure 2.21 - Common Elements (a) and Compounds (b) Copyright ©2016 Cengage Learning. All Rights Reserved. Representation of Pure Substances Elemental symbol: One- or two-letter abbreviation used to represent in writing the name of a chemical element Examples: H, Hydrogen; He, Helium Chemical formula: Symbolic representation of a molecule of a pure substance Combination of elemental symbols with subscript numbers showing the number of atoms in a molecule or formula unit Same as the symbol of the element for most elements Example: Sodium, Na Formulas of certain elements indicate the number of atoms of the element in the molecule Example: Hydrogen, H2 Copyright ©2016 Cengage Learning. All Rights Reserved. Representation of Pure Substances Formulas of multi-element molecules Examples Hydrogen chloride, HCl (Molecule contains one atom of hydrogen and one atom of chlorine) Water, H2O (A molecule of water contains two atoms of hydrogen and one atom of oxygen) Barium and chlorine atoms combine in a 1:2 ratio to form Barium Chloride Formula: BaCl2 Copyright ©2016 Cengage Learning. All Rights Reserved. Atoms and Molecules Atom - Smallest particle of an element Can combine with atoms of other elements to form chemical compounds Molecule - Smallest unit particle of a pure substance Can exist independently and possess the identity of the substance Copyright ©2016 Cengage Learning. All Rights Reserved. Atoms and Molecules Copyright ©2016 Cengage Learning. All Rights Reserved. Atom, molecule, compound video https://youtu.be/DkAXO--BYEw Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Which of these is macroscopic? Dry ice A neon atom A white blood cell Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Which of these is microscopic? Dry ice A neon atom A white blood cell Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Classify the underlined property as chemical or physical: The colorless liquid ethanol burns in air. Chemical Physical Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Classify the underlined property as chemical or physical: Ether is a colorless liquid that boils at 35 °C. Chemical Physical Copyright ©2016 Cengage Learning. All Rights Reserved. M/C Classify the underlined property as chemical or physical: The colorless gas propane cannot be liquified at temperatures above 97 °C. Physical Chemical Copyright ©2016 Cengage Learning. All Rights Reserved.