UNIT COVER PAGE Chem/Phys

Transcription

1 UNIT COVER PAGE Chem/Phys School District: Bremen Dist. 228 Department: Science Course: Chem/Phys Unit Title: Chemical Reactions Grade Levels: Signs of chemical reactions, writing word and chemical equations, balancing Topic Areas: equations, and identifying types of reactions. Time Frame: 3 weeks Date Created: 3/12/05 Date Modified: Unit Designer(s): Paul Switzer Link to State Standards C.5a Understand that in chemical reactions, atoms combine into molecules by means of bonds (e.g., by sharing electrons to form covalent or metallic bonds or by exchanging electrons to form ionic bonds). Know that ions are atoms or groups of atoms that have a positive or negative charge and that polyatomic ions are a group of covalently bonded atoms that act like a single atom when combining with other atoms. Understand that metals tend to form positive ions, and nonmetals tend to form negative ions. Understand that ionic solids like NaCl (sodium chloride, ordinary table salt) are formed from a three-dimensional repeating pattern of alternating positive and negative ions, held together by electrostatic forces (ionic bonds). Understand that the conservation of atoms in a chemical reaction, as summarized in a balanced chemical equation, leads to the ability to calculate theoretical masses of reactants and products. Understand how to read, interpret, and balance chemical equations. Analyze reactions (e.g., nuclear reactions, burning of fuel, decomposition of waste) in natural and man-made energy systems. Link to Department Learner Program Outcomes (LPO) TLW understand the terminology of science. TLW identify types of reactions. TLW identify and balance simple redox reactions. Summary of Unit Chemical reactions occur when atoms, molecules, or ions change in some way. Atoms. ions, and molecules break and form new bonds resulting in new substances. Signs that a chemical reaction has occurred include emission of a gas, a color change, formation of a precipitate, heat generation, and/or the absorption of heat. Chemists use chemical equations to represent the reactants and products of a chemical reaction. To be correct, a chemical reaction, the number of atoms on both sides of a chemical reaction must be equal. Many chemical reactions fit into one of five general types of reactions: synthesis, decomposition, single-replacement, doublereplacement, and combustion. 1

2 Resources Key Words chemical reaction product reactant Law of Conservation of Mass chemical reaction coefficient subscript synthesis decomposition single-replacement double-replacement combustion 2

3 STAGE 1: IDENTIFY DESIRED RESULTS Enduring Understandings Students will understand that: a chemical reaction is often accompanied by an emission of a gas, a color change, formation of a precipitate, heat generation, and/or the absorption of heat. by defining reactants and products and writing balanced chemical equations will help demonstrate the Law of Conservation of Matter. identifying reactions as synthesis, decompositions, single-replacement, doublereplacement, or combustion. Essential Questions 1. Explain the application of balancing equations to the Law of Conservation of Mass. 2. Write a word equation that describes the combination of baking soda and vinegar. 3. Why do chemists write chemical and word equations? 4. How do you know when a chemical equation is balanced? 5. What is a real-life situation that describes one of the five types of reactions? 6. What signs indicate that a chemical reaction has occurred? Knowledge and Skills Students will know the signs of a chemical reaction the application of the Law of Conservation of Matter to a balanced equation the 5 classes of reactions Students will be able to write word equations and chemical equations balance chemical equations classify reactions Students will be familiar with exothermic and endothermic reactions precipitate equilibrium reversible ring catalyst & inhibitors 3

4 STAGE 2: DETERMINE ACCEPTABLE EVIDENCE What evidence will show that students understand? Required Assessments (brief description) Letter to a scientist Other Assessments (brief description) Unit test Worksheets Essays Quizzes Demos & labs for reaction types Silver nitrate & copper wire Zinc & HCl Flinn balancing equations kit 4

5 Learning Activities PLAN LEARNING EXPERIENCES AND INSTRUCTION What sequence of teaching and learning experiences will equip students to develop and demonstrate the desired understandings? W How will you ensure that all students know where they are headed in the unit, why they are headed there, and how they will be evaluated? Demonstrate chemical reactions and write the word and chemical equations that describe the reactions. H How will you hook students at the beginning of the unit? Demonstrate examples of chemical reactions. Compare a chemical equation to a recipe for a chocolate cake. E What events will help students experience and explore the big idea and questions in the unit? How will you equip them with needed skills and knowledge? Bag of Reactions Lab and What is a Chemical Reaction Lab R How will you cause students to reflect and rethink? How will you guide them in rehearsing, revising, and refining their work? Students will write how-to instructions for balancing chemical equations. E How will you help students to exhibit and self-evaluate their growing skills, knowledge, and understanding throughout the unit? Students will demonstrate their ability to write word equations and balanced chemical equations. T How will you tailor and otherwise personalize the learning plan to optimize the engagement and effectiveness of ALL students, without compromising the goals of the unit? Students will identify one chemical reaction that he/she sees everyday and write a word equation that describes it. O How will you organize and sequence the learning activities to optimize the engagement and achievement of ALL students? Demonstrate chemical reactions Lab on signs of chemical reactions Writing word equations and chemical reactions Balancing chemical reactions Classifying types of reactions

6 Essential Questions at Topic Level Use the six facets of understanding to generate possible essential questions for the topic of your three-circle audit (curricular priorities). Explanation Interpretation What signs indicate that a chemical reaction has occurred? Explain the application of balancing equations to the Law of Conservation of Mass. Application Write a word equation that describes the combination of baking soda and vinegar. (Topic Area) Chemical Reactions Empathy What is a reallife situation that describes one of the five types of reactions? Self-Knowledge How do you know when a chemical equation is balanced? Perspective Why do chemists write chemical and word equations?

7 Student Performance Task Unit: Chemical Reactions Task: Applications/Perspective Course: Chem/Phys Time Frame: 1 class period & 4 days Overarching Understanding: Students will understand that science is not just a body of knowledge. It is a process by which many people continuously develop and refine our knowledge of the world around us. Enduring Understanding: Students will understand that a chemical reaction is often accompanied by an emission of a gas, a color change, formation of a precipitate, heat generation and/or the absorption of heat. Essential Question: Why do chemists write chemical and word equations? Vignette: You are a research scientist at Argonne National Laboratory reviewing the work of a fellow scientist. In the lab, you have repeated his experiment of combining baking soda and vinegar several times, and you have come to disagree with his conclusions. He stated that the reaction is a physical change; however, you feel differently. It is your job to write a formal letter to your fellow scientist using the standard formal letter writing format stating your own conclusions to the experiment. Be sure to cite clear evidence for your findings along with the proper chemical formula. Standard: You will be graded with the following rubric: Short rubric for formal letters (Writing Standards Handbook) 1 page, typed, size 12 font, single spaced Word equation presented correctly Formula equation correct and balanced Enough correct observations

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9 Performance Task Blueprint Unit: Chemical Reactions Type: Applications/Perspective Topic Area: Chemical Equations Time Frame: 1 class period & 4 days Goal To write a letter to another scientist describing a reaction that he or she has investigated. Role You are a research scientist at Argonne National Laboratory Audience Fellow scientist at Fermi Lab Situation You want this investigation to be relabeled from a physical change to a chemical change citing evidence & postulating the word reaction and formula reaction. Product or Performance A formal letter as in English class, 1 page typed, size 12 font, single spaced. Standards Short rubric for formal letters (Writing Standards Handbook) Word equation presented correctly Formula equation correct and balanced Enough observations and are correct

10 Creating Possible Performances Performance verb Generalization Performance Possible performances for Chemical Reactions (topic/unit) Facet One: Explanation 1. Explain the application of balancing equations to the Law of Conservation of Mass by conducting the bagging the gas lab & comparing the mass of the reactants before the reaction & then after and write a lab report. Facet Two: Interpretation 2. Explain the signs of chemical reactions by conducting several chemical reactions and observe gas emission, heat release, color change, and the formation of a precipitate. Facet Three: Application 3. Describe the reaction of vinegar & baking soda by writing a word equation. Facet Four: Perspective 4. Show the importance of writing chemical equations by writing a letter to another scientist describing a reaction that he/she performs. Facet Five: Empathy 5. Describe a real-life situation that illustrates one of the five types of reactions. by writing a short play School House Rock that symbolizes the type of reactions and explains it. Facet Six: Self-Knowledge 6. Explain how a chemist knows if a chemical equation is balanced by writing an essay.