Gases: Their Behavior and Properties

Transcription

1 Gases: Their Behavior and Properties Farmington Public Schools 10 th grade Chemistry - Academic 1

2 Table of Contents Unit Summary 3....page(s) Stage One: Standards Stage One identifies the desired results of the unit including the broad understandings, the unit outcome statement and essential questions that focus the unit, and the necessary knowledge and skills. The Understanding by Design Handbook, page(s) Stage Two: Assessment Package Stage Two determines the acceptable evidence that students have acquired the understandings, knowledge and skills identified in Stage One. 6 page(s) Stage Three: Curriculum and Instruction Stage Three helps teachers plan learning experiences and instruction that aligns with Stage One and enables students to be successful in Stage two. Planning and lesson options are given, however teachers are encouraged to customize this stage to their own students, maintaining alignment with Stages One and Two. 7.. page(s) Appendices page(s) 2

3 Unit Summary We live in an envelope of gases our atmosphere. Our lives are directly affected in terms of the weather, the air we breathe and the pressure of the gases on the surface of our bodies. This four week, 10 th grade chemistry unit is designed to explore the behavior and properties of gases using kinetic theory. This unit may be taught after atomic theory, intermolecular forces or stoichiometry. 3

4 Stage One: Standards Stage One identifies the desired results of the unit including the broad understandings, the unit outcome statement and essential questions that focus the unit, and the necessary knowledge and skills. The Understanding by Design Handbook, 1999 Essential Understandings and Content Standards #1 Scientific Inquiry is an ongoing process building knowledge about events and phenomena. The student will: 1.25 Frame, hypothesize, design, conduct, analyze, communicate and defend the results of controlled scientific experiment Discuss the validity of experimental results. #3 The composition and structure of matter determine the properties of matter Predict the results of chemical and physical processes based on atomic theory Illustrate that the behavior of gases can predicted based upon the motions and interactions of atoms. #4 The behavior of the physical world can be interpreted, understood and predicted in terms of a few fundamental principles Understand a variety of motions that matter exhibits Understand that matter interacts by way of forces, resulting in the changes of motion that drive our physical world. #5 The ever-changing composition and structure of the earth, its waters, and its atmosphere affect all life forms Evaluate how human activities have impacted the atmosphere, land and waters. 4

5 Unit Outcome Statement As a result of this unit, students will understand the importance of gases and the laws that govern gas behavior. The students will also understand that the behavior of gases can be seen and described: Through ideal mathematical relationships relating pressure, volume, temperature and quantities of gases to each other. Through the involvement of gases in chemical reactions By applying kinetic theory to the ideal behavior of gases Through the process of studying and explaining gas experiments Essential Questions Is there a finite set of rules and patterns that govern the natural world? Are human beings irrevocably changing our atmosphere? What is the point of studying ideal behaviors, if we live in a world of real behaviors? Knowledge and Skills Knowledge The Knowledge and Skills section includes the key facts, concepts, principles, skills, and processes called for by the content standards and needed by students to reach desired understandings. The Understanding by Design Handbook, 1999 Kinetic molecular theory Definition of pressure, temperature, volume, quantity(moles) Boyle s Law, Charles Law, Combined Gas Law, Ideal Gas Law Avogadro s Hypothesis Deviations of real gas behavior from ideal gas behavior Skills/Processes Unit conversions: pressure, temperature, volume, quantity Gas Laws calculations Perform gas based physical and chemical changes Graphing and drawing diagrams Thinking Skills Apply the kinetic molecular theory to explain relationships between gas variables Draw conclusions from laboratory data, supported by evidence Sort and categorize facts and observations in the authentic assessment Understand cause and effect as observed in the authentic assessment Make generalizations from ideal to real gas behavior Identify fact versus opinion, pro versus con with respect to environmental issues related to the atmosphere Stage Two: Assessment Package 5

6 Stage Two determines the acceptable evidence that students have acquired the understandings, knowledge and skills identified in Stage One. Authentic Performance Task The Demise of the USS Plainville The student takes on the role of a US Navy structural engineer Do an experiment to investigate one possible cause of a submarine accident: Could a rapid change in temperature contribute to the structural failure of a submarine? Data collection involves imploding an aluminum can representing the submarine. The student writes a report, in the form of a letter, to the Secretary of the Navy summarizing their conclusions supported by evidence, and with design change recommendations. Tests, Quizzes, and Other Quick and Ongoing Checks for Understanding Final unit exam in the appendix directly after the Demise of the USS Plainville as it has diagrams that are not supported by the word processing program Quizzes to assess student understanding and skills acquired over a portion of the unit. Projects, Reports, Etc. Practice questions and problems: to assess student understanding and skills for individual lessons Formal lab reports: to determine if students can gather data and interpret that data based upon prior knowledge Observations of students as they work in the laboratory: to assess laboratory skills and understanding Lab design: determining problem, independent and dependent variables, use of a control where appropriate, and writing complete procedures Graphic/symbolic organizer: completeness and quality of diagrams and written definitions/explanations of key terms and interplay of gas variables 6

7 Stage Three: Learning Experiences and Instruction Stage Three helps teachers plan learning experiences and instruction that align with Stage One and enables students to be successful in Stage Two. Learning Experiences and Instruction The learning experiences and instruction described in this section provide teachers with one option for meeting the standards listed in Stage One. Teachers are encouraged to design their own learning experiences and instruction, tailored to the needs of their particular students. 7

8 Lesson Topic Guiding Questions Suggested Sequence of Teaching and Learning Activities What is a gas? What s the matta with gases? Intro to gases 1 day The importance of studying gases 1 day Gas Variables 2 days Gas Relationships 1 day Formal Gas Laws 1 day Formal Gas Law Calculations 2 days Kinetic Molecular Theory 2 days Why do we study gases? What are the key variables used to describe gases? How are the gas variables related? What patterns emerge from our careful manipulations of volume? What types of graphs emerge? How are calculations done with the patterns discovered in the Boyle s Law and Charles Law labs? What generalizations to scientists make about the behavior of gases and the variables that describe gases? Use these questions as a hook into the subject. Derivation of the work gas. Importance of gases in the development of early experimental chemistry. Importance of gases in our lives. Demo: Vacuum pump/balloon, marshmallow, boil water at 50 o C Video: Gases in Our Lives Class discussion of our atmosphere, pollution, and global climate changes Definitions of volume, temperature, pressure, and quantity, and the various ways they are measured. Do associated demos. (student graphic-symbolic organizers for notes and discussion Homework: pg. 267 to 272, 330 to 332 of student textbook Students self-evaluate understanding of concepts Introduction to Gases lab Students manipulate balloons to make conclusions about how the gas variables affect each other. Quiz: on real world qualitative applications of the gas relationships Labs on Boyle s Law and Charles Law Analysis questions for homework Teacher modeling of representative problems Students do problems in class, alone or in small collaborative pairs Student worksheet for homework / or Problems from chapter questions of student textbook Quiz: on quantitative gas law problems Direct instruction on the assumptions of the kinetic molecular theory How do these assumptions explain the behavior of gases? Homework: section review 12.2 on pg. 332 of student textbook Kinetic Molecular Theory 1 day How do Cartesian divers work? Lab Creating Cartesian Divers 8

9 Avogadro s Hypothesis 1 day Properties of Selected Gases 1 days Applying Gas Behavior to Familiar toys 1 day Ideal Gas Law 2 days Our Environment 1 day Performance Task 2 days Unit Test 2 days How does the quantity of gas affect other gas variables? What are the properties of familiar gases? How do some familiar toys work? How does quantity (moles) of a gas affect gas variables calculations? Are Humans irrevocably changing our atmosphere? How will temperature change affect the integrity of a submarine? What do you need to understand about gases? Direct instruction: review calculating moles of a substance from grams Present Avogadro s hypothesis Demo: chemical reactions to generate and collect gases in a container that changes volume, example: NaHCO 3 and vinegar in plastic bottle with balloon over the mouth Lab: Micro-scale Gas Generation Culminating Activity: Students design a lab to identify an unknown gas sample The student can resubmit revised lab reports Students will manipulate a pulse-glass and a happy-bird. They will draw diagrams and write explanations of how these toys demonstrate gas behavior according to kinetic molecular theory Direct instruction of PV=nRT, use to describe ideal gases. Explanation of R the universal gas constant as a fundamental rate of energy transfer Student in-class problems and homework Worksheet: Ideal gas law Video: Planet Earth: The Climate Puzzle Class discussion on essential question before starting an essay. In-class essay on the guiding question Lab: The Demise of the USS Plainville Review for unit test In conjunction with the graphic-symbolic organizer (or notebook) and lab reports, students will use peer and teacher feedback to reflect on their understanding 9

10 Appendices Text: Chemistry: Addison-Wesley, Prentice Hall Publishing Lab Manual: Chemistry: Addison-Wesley Video: Gases in Our Lives, The Educational Film Center/ University of Maryland Video: The Atmosphere/ The Driving Forces, The Educational Film Center 10

11 THE DEMISE OF THE USS PLAINVILLE You are an engineer on the Naval Accident Investigations Task Force. You are studying the recent disaster involving the submarine USS Plainville, which sank while doing an extremely rapid dive in deep tropical waters. As naval engineer, you are aware that even in tropical water the temperature of deep water is significantly lower than at the surface. You will perform an initial experiment to investigate the effect of temperature change on a structure that is surrounded by water. The Secretary of the Navy is waiting for your report. He/she wants to know a. In your opinion, could temperature have been a contributing factor to this accident? Support your answer with data. b. What design changes would you recommend to prevent any further mishaps? The following list of apparatus is available to you. Soda cans Ring stand, iron ring and Bunsen burner Or a hot plate A container for an ice bath Tongs Ice 100 ml and 10 ml graduate cylinders Criteria for grading Observations are complete, describing everything that happens to the can Data table is well designed, clear and easy to read. Answer fully the attached questions Write a full report to the Secretary of the Navy. Spelling and grammar will count. The two points listed above should be fully addressed. 11

12 Name Date Period PROCEDURE 1. Measure the volume of the can and record this volume. 2. Record the stated volume of the can. 3. Calculate the difference between the two volumes and record this result. 4. Set up an ice water bath. Stir the ice until most of the ice melts. 5. Add 3 to 5 ml of water to the can. 6. Heat the can until the water is steaming. 7. Using the tongs, invert the can and quickly plunge the can into the ice water bath. This must be done very quickly. If your can does not implode, you either did not invert the can completely, or you did not do the maneuver quickly enough or both of these reasons. This means you must start again with this can at step 5. If the can is damaged, then start at step 1 with a new can. 8. Lift the can out of the water. 9. Measure the volume of the can after it has imploded. Record this amount. A. Observations B. Data Table 12

13 Name Date Period Analysis: 1. For each part below (a, b, c) Draw a diagram of the can that shows the motion of the gas particles inside the can and outside the can. Use little dots with arrows attached. If appropriate, indicate if gas particles are entering or exiting the can Label relative high, low or equal pressure areas Label relative high, low or equal temperature areas a. While the can is being heated and the added water is boiling. b. Just as the can enters the ice water bath. c. After the can is in the ice water bath and has imploded. 13

14 2. Which variable did you have control over? 3. Would this variable be considered an independent or dependent variable? 4. In terms of kinetic molecular theory, what happened to the gases inside the can a. When the can was heated? b. In the ice water bath? 5. What is the percent change in volume for your can? Show all calculations for full credit. Extra Credit: Why did you need to invert the can when you plunged it into the bath? 14

15 Name Date Period Dear Secretary of the Navy, 15