detailed unit

Title: Exploring Systems: Reactions and Conditions Subject: Chemistry

Topics: Chemical reaction systems, physical systems, kinetic molecular theory, solutions, factors affecting systems, equilibrium, Le Chatelier & Haber, acids & bases

Grade: HS Designers: Laura Kernigan, Bobby Tams, Miriam Jordan, Cheryl Thomasson

Introduction Unit Framework Title Exploring Systems: Reactions and Conditions Unit Framework Annotation The underlying themes in this unit are systems and equilibrium. Energy and its relation to molecular motion, endothermic and exothermic processes, and states of matter are taught in that context. Topics include specific heat, solutions, molality, colligative properties, acids and bases, and behavior of gases. The mole concept and stoichiometry are extended in this unit to limiting reactants and percent yield. A broader understanding of acids and bases is developed in the context of equilibrium. Le Chatelier’s Principle will be applied to chemical reaction systems. The action of a catalyst is investigated and illustrated using energy diagrams. The sequence of lessons, tasks, and labs in this unit illustrate how instruction can be organized to implement the GPS. The activities and tasks are suggested but should be adjusted, omitted or enhanced as needed for specific class situations. Some classes may need more time, practice, or instruction for some concepts. Others may need less time. Therefore, the numbering of days is given only as a guide which should be flexible. This can be done without sacrificing the quality of the unit. Approximate Duration for the Unit Framework Approximately 6 weeks on 4 x 4 Block Authors Laura Kornegay, Bobby Timms, Miriam Jordan, Cheryl Thomasson Email Address

Standards Focus Standards SC6. Students will understand the effects motion of atoms and molecules in chemical and physical processes.

a. Compare and contrast atomic/molecular motion in solids, liquids, gases, and plasmas. b. Collect data and calculate the amount of heat given off or taken in by chemical or physical processes. c. Analyze (both conceptually and quantitatively) the flow of energy during change of state (phase).

SC7. Students will characterize the properties that describe solutions and the nature of acids and bases.

a. Explain the process of dissolving in terms of solute/solvent interactions: •Observe factors that effect the rate at which a solute dissolves in a specific solvent, •Relate molality to colligative properties.

b. Compare, contrast, and evaluate the nature of acids and bases: •Strong vs. weak acids/bases in terms of percent dissociation •Bronsted-Lowry •pH

SC2. Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

c. Apply concepts of the mole and Avogadro’s number to conceptualize and calculate molar volumes of gases. d. Identify and solve different types of stoichiometry problems, specifically relating mass to moles and mass to mass. e. Demonstrate the conceptual principle of limiting reactants. f. Explain the role of equilibrium in chemical reactions.

SC5. Students will understand that the rate at which a chemical reaction occurs can be affected by changing concentration, temperature, or pressure and the addition of a catalyst.

a. Demonstrate the effects of changing concentration, temperature, and pressure on chemical reactions. b. Investigate the effects of a catalyst on chemical reactions and apply it to everyday examples. c. Explain the role of activation energy and degree of randomness in chemical reactions.

SCSh1. Students will evaluate the importance of curiosity, honesty, openness, and skepticism in science.

c. Explain that further understanding of scientific problems relies on the design and execution of new experiments which may reinforce or weaken opposing explanations.

SCSh2. Students will use standard safety practices for all classroom laboratory and field investigations. a. Follow correct procedures for use of scientific apparatus. b. Demonstrate appropriate techniques in all laboratory situations. c. Follow correct protocol for identifying and reporting safety problems and violations. SCSh3.Students will identify and investigate problems scientifically.

b.Suggest reasonable hypotheses for identified problems. c.Develop procedures for solving scientific problems. d.Collect, organize and record appropriate data. e.Graphically compare and analyze data points and/or summary statistics. f.Develop reasonable conclusions based on data collected.

SCSh4.Students will use tools and instruments for observing, measuring, and manipulating scientific equipment and materials. b.Develop and use systematic procedures for recording and organizing information. c.Use technology to produce tables and graphs.

SCSh5.Students will demonstrate the computation and estimation skills necessary for analyzing data and developing reasonable scientific explanations. b. Consider possible effects of measurement errors on calculations. d. Solve scientific problems by substituting quantitative values, using dimensional analysis, and/or simple algebraic formulas as appropriate.

SCSh6.Students will communicate scientific investigations and information clearly. b.Write clear, coherent laboratory reports related to scientific investigations. c.Write clear, coherent accounts of current scientific issues, including possible alternative

interpretations of the data. d.Use data as evidence to support scientific arguments and claims in written or oral

presentations. e.Participate in group discussions of scientific investigation and current scientific issues.

SCSh7.Students will analyze how scientific knowledge is developed. b.The universe is a vast single system in which the basic principles are the same everywhere. c. Universal principles are discovered through observation and experimental verification. d. From time to time, major shifts occur in the scientific view of how the world works.

More often, however, the changes that take place in the body of scientific knowledge are small modifications of prior knowledge. Major shifts in scientific views typically occur after the observation of a new phenomenon or an insightful interpretation of existing data by an individual or research group.

SCSh8.Students will understand important features of the process of scientific inquiry. b.Scientific investigators control the conditions of their experiments in order to produce c. valuable data. d.The ultimate goal of science is to develop an understanding of the natural universe which is free of biases.

SCSh9.Students will enhance reading in all curriculum areas by: a.Reading in all curriculum areas

• Read technical texts related to various subject areas. • Discussing books • Discuss messages and themes from books in all subject areas. • Relate messages and themes from one subject area to messages and themes in another area. • Evaluate the merit of texts in every subject discipline. • Recognize the features of disciplinary texts.

c. Building vocabulary knowledge • Demonstrate an understanding of contextual vocabulary in various subjects. • Use content vocabulary in writing and speaking. • Explore understanding of new words found in subject area texts.

d. Establishing context • Explore life experiences related to subject area content.

Complementary Standards (optional)

Understanding and Goals Unit Understandings, Themes, and Concepts • A system is all the components that define what is being observed or studied. In open systems matter and

energy can enter and/or leave the system. In closed systems matter and energy are confined to the system. • The energy changes in chemical and physical systems are consistent with the Law of Conservation of

Energy. The transfer and conversion of energy from one form to another drive molecular motion and phase change (change of state). This energy can be measured and calculated, based on a substance’s physical constants such as heat of formation, heat of hydration, and specific heat.

• The state of matter for a substance is determined by the substance’s temperature (average kinetic energy)

and pressure of the system. This data can be plotted on a phase change diagram to illustrate the flow of energy through change of state.

• Chemical reactions are systems that involve matter and energy in the rearrangement of atoms and ions into

different patterns. • Chemical reaction systems are affected by the physical conditions of the system, including energy,

temperature, pressure, concentration, particle size, and solubility, and by the presence of a catalyst.

• The concept of equilibrium can be applied to physical systems, solutions, and gases as well as to chemical

systems such as acids. Misconceptions: Students may think that: Water becomes hydrogen and oxygen when it evaporates. All substances “boil” and “freeze” at the same temperature regardless of their chemical composition and factors such as pressure and colligative properties. Acids are more dangerous than bases. In the acid/base concept, strong refers to concentrated and weak refers to dilute. Acids “eat” (destroy) metals. In a chemical reaction everything is consumed and there are no reversible processes. Language solute, solvent, solvation, solutions, molarity, molality, colligative, concentration, molar volume, specific heat, phase change, heat of fusion, heat of vaporization, joules, calories, exothermic, endothermic, stoichiometry, limiting reactant, percent yield, neutralization, equilibrium, weak/strong acid or base, pH, Bronsted-Lowry, titration, Le Chatelier’s Principle, endothermic, exothermic, catalyst Essential Questions (Additional guiding questions are included in daily lessons.)

• How can physical and chemical events be understood as systems? • How does the Law of Conservation of Energy apply to a system? • How does the system and the environment outside a system change after an endothermic or exothermic

event? • Water boils at 68oC on Mt. Everest. Would that cook an egg? • Why would a NASA scientist need to be very familiar with the phase diagram of oxygen? • How do changes in the physical conditions affect a chemical or physical system? • How is stoichiometry in chemistry like bookkeeping in a business? • Do recipes have limiting reactants? • Why is it difficult for a manufacturer to achieve a 100% yield on his product? • How has our understanding of acids and bases changed from Arrhenius to Bronsted and Lowry?

(Whose acid is it anyway? and what’s the difference?) • How do changes in temperature, pressure, and concentration affect a chemical reaction? • How do catalysts affect chemical reaction systems? • How important are communication and collaboration in scientific investigations and technological

advances? • How can you use the Bronsted-Lowry Model to describe equilibrium in a carbonated drink? • How can the combined understandings gained in this unit explain the chemistry of a soft drink? • How would you test an antacid to determine its effectiveness?

Balanced Assessments Method or type

Informal Observations

Dialogue and Discussion

Selected Responses

Constructed Responses

Self-Assessments

Description White boards are squares cut from a sheet of white shower board. They can be written on with dry erase markers like an old fashioned slate.

Monitor when working Stoichiometry mass/mass, mole/mass and molar volume problems. Use white boards to display work Given stresses to a system, students will give draw arrows to indicate direction of equilibrium in reactions. (white boards)

Assess prior knowledge through discussion of demonstrations and informal questions. Conferences during individual and group tasks on: heat and energy; temperature, pressure and volume; equilibrium; evaporation; dissolving process; Le Chatelier’s principle. Create common analogies to limiting reactants. After building a mock catalytic converter give a brief description of the parts.

Given balanced thermochem-ical equations, identify correct energy graphs. Quiz over properties of gases Equilibrium quiz on general principles. Bell ringer quiz(s) on stoichiometry.

Specific heat lab Specific heat problems/quiz Heat of fusion lab Rate of solution lab Colligative property lab Boyle’s Law Lab (optional) Charles’ Law Lab (optional) Develop a pH scale with a plant extract indicator. Bronsted-Lowry bell-ringer problems. HCl/NaOH limiting reactant and percent yield lab

Self/ peer check homework problems Molality problems Interactive software for working problems

Unit Performance Task(s)

Unit Performance Tasks The Life of a Snowflake Performance Task Your task: Trace the progression of a snow flake in a cloud through precipitation onto a road surface, the addition of salt by the transportation department and evaporation

back into the cloud. Include energy flow through phase changes, temperature changes, solvation, colligative properties, and gas laws. For the purpose of this assignment, assume this snow flake is in a closed system that encompasses a particular volume of atmosphere and an area of land. Work individually or in groups of 3 or 4, as determined by the teacher. Project format may be a multimedia presentation, tri-fold project board, paper, or video. The length of the project is not as important as the content. Antacid Lab and Project: Design and perform an experiment to determine the most effective antacid. Then create an “info-mercial” to promote this antacid. Priestley’s Birthday Party: Students imagine that Arrhenius, Bronsted and Lowry, Lewis, Haber, and LeChatlier are gathered at Joseph Priestley’s birthday party, where Priestley is serving his new invention, soft drinks (carbonated water in sealed containers). Just imagine the conversation that would take place. Each man would want to explain those little fizzy bubbles from their own perspective. Research and write an essay comparing and contrasting each man’s ideas and what he would emphasize about acidity of the drink and the equilibrium of the drink before it was opened and after it was opened. Be prepared to take the part of any one of these men when called upon to do so on Day 28. Description/Directions For complete directions and descriptions click on each task or scroll to the appendix of tasks and activities located at the end of this document. Rubric for Performance Task Rubrics are in progress. Teacher created rubrics should use the appropriate GPS elements as criteria.

Student Work Sample with Teacher Commentary Sequence of Instruction and Learning

List and briefly describe the sequence of teaching strategies, teaching activities, and learning activities that will guide students to attainment of the intended standards.

Sequence of Instruction and Learning Teacher Activities Lead brainstorming discussions Introduce system concept Explain interaction of energy and matter Facilitate construction of heating/cooling curve Introduce dynamic equilibrium Illustrate and model specific heat calculations and calorimetry calculations Explain phase change diagrams Demonstrate and explain colligative properties Model stoichiometric calculations and strategies including molarity, molality, and gas laws, (optional) Guide student practice on problems Teacher discussion and demonstrations to illustrate equilibrium, Bronsted-Lowry, stoichiometry and limiting reactants Facilitate work in groups

Student Activities Brainstorm systems Analyze a system Create language word wall Create and explain graphic organizer for phases of matter Construct a heating/cooling curve Perform calorimetry lab Solve heat of hydration calorimetry problems Specific Heat Inquiry Calorimetry quiz Interactive work with phase change diagrams Rate of solution lab and class data discussion Coligative properties lab Construct the heating curve of lauric acid Exploratory activity with Cartesian divers Gas laws labs (optional) Use white boards to display answers Conduct acid base labs

Sequence of Activities, Tasks, and Assessments for Unit

Sequence of Activities, Tasks, and Assessments for Unit 5

Day 1

EQ: How can physical and chemical events be understood as systems? Guiding questions:

• How does a closed system differ from an open system? • What type of system is a chemical reaction? • What are the similarities and differences of freezing water and burning wood?

Understanding: A system is all the components that define what is being observed or studied. In open systems matter and energy can enter and/or leave the system. In closed systems matter and energy are confined to the system. Have students Brainstorm a list of systems. Discuss the concept of closed and open systems in chemical and physical processes Reinforcement activity (Due Day 4) Students will form groups and begin this task. Introduce thermochemistry with emphasis on endo/exothermic energy diagrams of chemical reactions Use video clips and web pages for visual reinforcement. Assign Homework : Endothermic/Exothermic. The following clips & web pages were active at the time of this posting: http://www.harcourtschool.com/activity/states_of_matter/, (Kinetic Theory of gases only) http://www.falstad.com/gas/, (Kinetic Theory with velocity) http://zebu.uoregon.edu/2000/ph102/ex2.html http://public.lanl.gov/alp/plasma/ubiquitous.html (Plasma) http://www.ornl.gov/sci/fed/Theory/tt/ttmcp/plasma.htm (Four states of matter graphic) http://fusioned.gat.com/images/pdf/Plasma_4th%20State_of_Matter.pdf (Multimedia presentation on plasma)

Day 2

EQ: How does the Law of Conservation of Energy apply to a system? How does the system and the environment outside a system change after an endothermic or exothermic event? Understandings: The energy changes in chemical and physical systems are consistent with the Law of Conservation of Energy. The transfer and conversion of energy from one form to another drive molecular motion and phase change (change of state).

Activate this lesson with a language preview lesson: At this early point in the unit it would be good practice to preview the language of the unit (vocabulary). A word wall with a different view is one way to involve the students in this. Continue with group instruction by going over homework and informally assess for understanding (raise hands, white boards). Introduce or review kinetic theory and link to the concept of endothermic/exothermic change. Exothermic literally means “go out heat.” Endothermic means “come in heat.” Heat will enter or leave a system during these processes. Have students create a graphic organizer on the difference in the motion of particles in solids, liquids, gases, and plasmas. The organizer should illustrate relative distance between particles and the students should explain how this relates to energy of the particles and therefore to the distinguishing physical properties of each state. Discuss how this also relates to the energy changes involved in evaporation. Students summarize lesson by explaining their graphic organizer to another student.

Day

3+

This lesson continues instruction and exploration of the essential question and understanding from the previous lesson. Build on the understanding of kinetic theory of matter and states of matter and energy, to explain a heating/cooling curve. Introduce the concept that dynamic equilibrium exists when two reversible processes occur at the same rate. When a solid dissolves in a liquid or a liquid evaporates, a dynamic equilibrium exists at the interface between the two components. Students will conduct the Heating curve lab using H2O Student summarizes understanding in a lab report. As an extension and enrichment of this lab or as a performance assessment task students could carry out the Performance Task , of determining the heating curve of lauric acid. Teacher note: An extra day would be needed to complete the lauric acid is task. Day 10 is arbitrarily left blank as a possible time that this task or another enrichment or modification could be inserted.

Teacher Note on Safety: Review and require students to follow all appropriate lab safety rules, including the wearing of goggles and aprons, clothing safety and the handling of

corrosive chemicals and how to waft to detect odors. Students must be thoroughly knowledgeable about the use of safety equipment including the shower, eyewash, sinks, and fire extinguisher.

http://www.science.uwaterloo.ca/~cchieh/cact/c123/heating.html (description of heating curve) http://www.dlt.ncssm.edu/TIGER/Flash/phase/HeatingCurve.html (graphic of water & heating curve) http://netcamp.prn.bc.ca/nuggets/heatingcurve.swf (graphic heating curve)

Day 4

EQ: How does the Law of Conservation of Energy apply to a system? EQ: How does the system and the environment outside a system change after an endothermic or exothermic event? Understandings: The energy changes in chemical and physical systems are consistent with the Law of Conservation of Energy. The transfer and conversion of energy from one form to another drive molecular motion and phase change (change of state). This energy can be measured and calculated, based on a substance’s physical constants such as heat of formation, heat of hydration, and specific heat. Introduce and discuss of scientific and every day applications of specific heat capacity. Illustrate how the relatively high specific heat of water is important for moderating temperature on earth. Model calculations of specific heat and calorimetry. Students complete the exploratory Specific Heat Capacity task. Students work specific heat and calorimetry problems in class and answer questions using pair/share strategy. Assess informally with white boards. Home work: Assign problems and questions on heating curve, specific heat, heat of fusion, and heat of vaporization.

Teacher Note on Safety: Review and require students to follow all appropriate lab safety rules, including the wearing of goggles and aprons, clothing safety and the handling of corrosive chemicals and how to waft to detect odors. Students must be thoroughly knowledgeable about the use of safety equipment including the shower, eyewash, sinks, and fire extinguisher.

Day 5

This lesson continues the essential questions and understandings from Day 4. *DONOW: Work with a partner to check answers to homework. (self/peer assessment) Begin class with a discussion of endothermic/exothermic processes. Dispel misconceptions with examples and demonstrations. Students will practice calorimetry to measure the heat of hydration for anhydrous copper sulfate. (Calorimetry) This CuSO4 water of hydration lab explores an exothermic process. Students will summarize this lab in a written lab analysis.


Homework: Prepare for a quiz on heating curves and calorimetry

* Teacher note: A DONOW is a student activity that the teacher posts prominently on the board. Students can be trained to look for the DONOW upon entering the class and to “DO it NOW”. This management technique organizes time and effort effectively and allows the teacher to circulate in the class or to attend to individual student needs briefly at the start of class. If the teacher has to spend time answering and explaining it over and over, that defeats the purpose. Make it clear and simple to follow; keep it doable although it might be thought provoking or challenging.

Day 6

E.Q: Water boils at 68oC on Mt. Everest. Would that cook an egg? E.Q: Why would a NASA scientist need to be very familiar with the phase diagram of Oxygen? Understandings: The energy changes in chemical and physical systems are consistent with the Law of Conservation of Energy. The transfer and conversion of energy from one form to another drive molecular motion and phase change (change of state). The concept of equilibrium can be applied to physical systems, solutions, and gases as well as to chemical systems such as acids. At the beginning of this class period students complete a quiz over heating curves and calorimetry See. Heating Curve/Calorimetry Quiz for example quiz items. Use the essential questions to hook students into this lesson. After this discussion, introduce the phase change diagram for water. If pressure and temperature are plotted on a graph, the result is a phase diagram which is a convenient graph for discussing the energy flow through states of matter. Explain the meaning and importance of a phase diagram for understanding energy flow One useful teaching strategy is to have students use websites that provide some interactive data. One resource for this is: http://www.wwnorton.com/chemistry/tutorials/ch9.htm (See tutorial on phase diagram) Concept quiz (energy, phase diagram)

Day 7

EQ: How does changing the physical conditions, for example, disturbing the dynamic equilibrium at the interface between a solid solute and a liquid solvent, promote solvation?

• How does stirring increase the solubility rate in most solutions? Understandings: Chemical systems are affected by the physical conditions of the system, including energy, temperature, pressure, concentration, particle size, and solubility, and by the presence of a catalyst.

The concept of equilibrium can be applied to physical systems such as solutions and gases as well as to chemical systems such as acids.

• Specific understanding introduced in this lesson: Dynamic equilibrium exists when two opposing processes occur at equal rates. When a solid dissolves in a liquid, a dynamic equilibrium exists at the interface between the two components.

This lesson will center around three of the conditions that affect rate of solution: agitation, temperature and particle size. Begin this lesson with an introductory discussion of solvation and equilibrium. Model solvation process for salt and water. The group inquiry for this lesson is (Rate of solution). Have students discuss their results. Continue the discussion of salvation now that students have had hands-on experience with factors that affect solvation. Have students complete their lab reports for this task. http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf


Days 8-9

EQ: How do changes in the physical conditions affect a chemical or physical system? • Why do we salt icy roads and add salt when cooking spaghetti? • When do we need to have antifreeze in our radiators? • Why happens when you attempt to dissolve sugar in hot tea? Ice tea? • Why might the Department of Transportation use CaCl2 instead of NaCl on icy

roads? Understandings: Chemical and physical systems are affected by the physical conditions of the system, including energy, temperature, pressure, concentration, particle size, and solubility, and by the presence of a catalyst. The concept of equilibrium can be applied to physical systems, solutions, and gases as well as to chemical systems such as acids. (Review the understandings from lesson 6, Exploring Change Unit, for structure and unique properties of water.) Dispel any misconceptions that water is the only solvent. Water is the most common solvent known to man, but many other solvents exist. In any solution the component that is present in the greater amount is the solvent for that solution. Explain and demonstrate molarity and molality. Explain the difference in what each measures.

Link molality to colligative properties of aqueous solutions. Explain and demonstrate practical examples of the effects of colligative properties. Model molality problems then provide time for guided practice working these problems. http://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-melts-ice.shtml Students conduct Colligative properties lab.


Model colligative property problems. Facilitate guided practice for solving problems. Assign homework of molality, freezing point depression and boiling point elevation. Assign Performance Assessment Task, Life of a Snowflake, to complete for Day 15.

Day 10

Day for completing extension and enrichment tasks. See day 3.

Day 11

EQ: How do changes in the physical conditions affect a chemical or physical system?

• What factor(s) determine(s) if one substance floats or sinks in another substance? Understanding: The concept of equilibrium can be applied to physical systems, solutions, and gases as well as to chemical systems such as acids. Specific understandings in this lesson:

• A Cartesian diver demonstrates dynamic equilibrium between pressure and volume and density of a gas. The buoyant force exerted on the gas filled diver is equal to the mass of the volume of water which is displaced by the diver.

Activate this lesson with some interesting variations of the Cartesian diver. See websites for ideas. Have students make 20 oz. soda bottle Cartesian divers and let them explore how applying force to the container affects the diver. Have them try to predict and explain these effects. They should record data about their different attempts. Discuss the results with the class. *Teacher Note: This activity usually uncovers various misconceptions. Rather than addressing these immediately, use what the students are saying to inform your discussion with them about the movement of molecules of gas and the affect of pressure on the motion and density of these molecules in a physical system (Boyle’s Law). *Teacher note: The activity written up at this website is an example of how this lesson could be arranged as an inquiry lesson, allowing students to apply the characteristics of science to discovering and discussing scientific principles. http://www.pbs.org/wgbh/nova/lasalle/buoyancy.html

also see: http://www.ed.uiuc.edu/courses/CI241-science-Sp95/resources/philoToy/philoToy.html Conceptually explain the relationship between pressure and volume. Discuss practical applications of Boyle’s Law.. Students summarize by writing their explanation of the Cartesian diver explaining the effect of pressure on the motion of molecules in a closed system (Boyle’s Law). At this point, the student should recognize that the Cartesian diver is an example of a system and use the concept of a system in their explanation.

Day 12

EQ: How do changes in the physical conditions affect a chemical or physical system? E. Q.: What happens to the pressure and temperature of the air in your tires as you drive from school to home? Why do tire manufacturers suggest slightly deflating tires in the summer? Why do weather balloons expand from a 6 foot diameter to a 20 foot diameter as it rises into the atmosphere? Understandings: Chemical and physical systems are affected by the physical conditions of the system, including energy, temperature, pressure, concentration, particle size, and solubility, and by the presence of a catalyst. Understanding: The concept of equilibrium can be applied to physical systems, solutions, and gases as well as to chemical systems such as acids.

• The relationship between gases, temperature, pressure, and volume can be expressed mathematically.

Activate this lesson by randomly selecting and reading explanations of the Cartesian diver from the previous lesson. The authors of the explanations should remain anonymous. Have class thumbs up or down for each explanation. Be alert for lingering misconceptions and discuss these. Demonstrate the effect of changing temperature on a gas system. Students can experiment with a simulation of the variables of temperature and volume at: Charles’ Law http://www.chm.davidson.edu/ChemistryApplets/GasLaws/CharlesLaw.html) Students can collect data and graph the relationship of volume to temperature by conducting the Charles’ Law Laboratory Activity . Complete graph and lab report. Teacher Note on Safety: Review and require students to follow all appropriate lab safety rules, including the wearing of goggles and aprons, clothing safety and the handling of corrosive chemicals and how to waft to detect odors. Students must be thoroughly knowledgeable about the use of safety equipment including the shower, eyewash, sinks, and fire extinguisher. Teacher Note: The GPS do not require students to master the calculations involved in the gas laws. However they are included here as an example of where they could fit in a GPS unit.

Day 13

Days 13 and 14 are planned as optional extensions of day 12. If gas law calculations are being taught, have students review what they have learned to describe the relationships between pressure, temperature and volume, and then translate these into mathematical expressions.. Explain standard temperature and pressure and the Kelvin temperature scale. Model calculations and review dimensional analysis as needed. Provide guided practice on gas law calculations. Assign homework on gas laws (conceptual & quantitative). Ticket out the door: A completed sample of a Boyle’s Law and a Charles Law calculation.

Day 14

DONOW: Check gas law homework with a partner. (conceptual & quantitative) Optional time is allotted here for students to further investigate the behavior of gases through lab activities and calculations.

Day 15

Snowflake Culminating Activity Day : Students present their projects and participate in a fishbowl discussion.

Day 16-17

EQ: What type of system is a chemical reaction? EQ: How is stoichiometry in chemistry like bookkeeping in a business? Understandings:

• Chemical reactions are systems that involve matter and energy in the rearrangement of atoms and ions into different patterns.

• Matter is neither gained nor lost in a chemical reaction but atoms and ions are rearranged into different patterns, bonds are broken and /or formed, and energy is stored or released. (This understanding was introduced in the Unit, Exploring Change.)

• The mole is the fundamental unit for amount of substance that is used in stoichiometric calculations.

Activate this lesson by having students modify the word wall by adding new words and revisiting previously used words. Review the mole concept and discuss how it relates to balancing chemical equations. http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/limitr15.swf Review the skills for balancing equations as needed. Teach mass-mole or mass-mass stoichiometry problems. Make applications to real-life chemistry. Provide guided practice, allowing students to work individually or in groups. Give clear feedback as students work. Use interactive software (if available) for practicing stoichiometry problems. http://www.programurl.com/ebas.htm http://www.trinityfiles.com/soft/Education/Science/chemcalcs.htm http://www.geocities.com/tjachem/ http://gemini.tntech.edu/~snorthrup/chem111/tutorials/chap3b/start.html (good practice quiz) Homework: This can be differentiated, based on the needs of the students for this lesson. It should cover a review of balancing equations, and the mole concept, as well as stoichiometric problems.

Days

18/ 19

DONOW: Students check answers for homework. Peer teach or remediate as needed. Initiate class with the Bell ringer quiz for stoichiometry. EQ: Do recipes have limiting reactants? EQ: Why is it difficult for a manufacturer to achieve 100% yield of his product? Understandings Chemical reactions are systems that involve matter and energy in the rearrangement of atoms and ions into different patterns. Matter is neither gained nor lost in a chemical reaction but atoms and ions are rearranged into different patterns, bonds are broken and /or formed, and energy is stored or released. (This understanding was introduced in the Unit, Exploring Change.) Understanding specific to this lesson: If arbitrary amounts of reactants are combined in a reaction generally one of the reactants will be used up completely (limiting reactant), while an excess amount of the other reactant(s) will remain when the reaction has run to completion. The limiting reactant will then determine the yield of the product. Engage students in limiting reactants by giving them scenarios to formulate analogies for every day life . http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/limitr15.swf Introduce and practice limiting reactant and percent yield mathematically as a prelab activity. Students carry out a limiting reactant and percent yield lab, collecting real data for calculating percent yield.


For further understanding, have students work stoichiometry, limiting reactant and percent yield problems in class. This can be done with students showing answers on white boards, working individually, or as partners, or with peer tutoring. The teacher can differentiate with problems of varying complexity for students. However this practice is done, monitor and check for understanding, and adjust instruction accordingly. Optional homework assignment: Have students prepare an “edible indicator” to be used in lab during the next class. See Cabbage Juice Indicator Lab directions for Day 20.

Day 20

E Q: Advertisers use the phrase, “pH balanced.” What does that mean? Understanding: The concept of equilibrium can be applied to physical systems, solutions, and gases, as well as to chemical systems such as acids. Specific Understandings:

• Typical acids and bases are solutions that contain an excess of either hydronium ions(acids) or hydroxide ions (bases).

• Pure water contains an equal number of hydronium and hydroxide ions. • pH is a measure of the hydronium ion concentration in a solution. • A change in H+ or OH- concentration in a solution causes the pH to fluctuate. • Some acids and bases dissociate easier than others thus having a greater effect on pH.

Activate this lesson with a display of common acids and bases. Demonstrate neutralization using universal indicator. Review lab from Day 19 and discuss implications of limiting reactants for the process of neutralization. Discuss or review naming of acids and characteristics of acids, bases and neutralization reactions. (Review unit three, Exploring Change.) Explain the concept of pH by discussing first the concentration of hydronium and hydroxide ions in pure water being equal at 1X10 -7 moles/L. Any addition, removal, bonding, or releasing of either ion will cause the solution’s balance of ions to shift to be either more acidic or more basic. Students will carry out the Edible Indicator lab as an inquiry activity to develop a pH scale. Introduce this lab activity with information about the chemical nature of indicators. They are themselves weak acids/bases that exhibit different colors depending on which form they are in. Students proceed with the indicator lab.


Days 21-22

EQ: How has our understanding of acids and bases changed from Arrhenius to Bronsted-Lowry? (or whose acid is it anyway? and what’s the difference?) Understanding: The concept of equilibrium can be applied to physical systems, solutions, and gases, as well as to chemical systems such as acids. Specific Understandings:

• From Arrhenius’ definition of acids having hydrogen (hydronium) ions in solution and bases having hydroxide ions in solution, the concept of acids and bases has been refined and can be understood in terms of hydrogen ion donors (acids) or acceptors (bases). Bronsted and Lowry generalized the definitions to a more to theoretical level: acids are proton donors; bases are proton acceptors.


The hook to this lesson is the presence of “fizz”. Do demonstrations involving soft drinks (or club soda, which is less messy) to illustrate the concepts in this lesson. Determine the pH of several

drinks. Check immediately upon opening and again at intervals with narrow range pH paper. Other more dramatic demonstrations can be done by acquiring some dry ice, solid CO2, which can be added to water with various indicators for vivid color results and changes. Use the demonstrations to introduce strong/weak acids/bases in terms of percent dissociation. Write chemical equations for ionization of each. Use the equilibrium of H2O + CO2 H2CO3 as one example. Have students explore strong/weak acids/bases through a titration activity. Students might use the homemade indicators from the previous class as well as standard indicators. Explain that most chemical indicators work because they are weak acids/bases themselves and change color as their hydrogen ions are transferred. Discuss the concept of equilibrium in an acid base system. Students summarize lesson by updating word wall to include acid/base language.

Day 23

EQ: How do changes in temperature, pressure, and concentration affect a chemical reaction? Understandings: When a chemical system is acted upon by a stress, such as a change in temperature, pressure, of concentration of reactant(s) or product(s), the system reacts in such a way as to relieve that stress. Interacting units of matter tend toward equilibrium states in which the energy is distributed as randomly and uniformly as possible. Discuss and demonstrate stresses (especially temperature and concentration) to equilibrium systems using Le Chatelier’s Principle. Using soft drink examples throughout will help the student to understand what is expected in the culminating activity. Discuss the Haber process. Have students consider a variety of stresses to a system. Using the white boards, the students will draw an arrow in the direction of the equilibrium shift. This can be done using the white boards. Assign the culminating task for this unit, Priestley’s Birthday Party Students imagine that Arrhenius, Bronsted and Lowry, Lewis, Haber, Le Chatelier, Henry, and others you may add, are gathered at Joseph Priestley’s birthday party, where Priestley is serving his new invention, soft drinks (carbonated water in sealed containers). Just imagine the conversation that would take place. Each man would want to explain those little fizzy bubbles from their own perspective. Research and write an essay comparing and contrasting each man’s ideas and what he would emphasize about acidity of the drink and the equilibrium of the drink before it was opened and after it was opened. Be prepared to take the part of any one of these men when called upon to do so on Day 27. Teacher Note: Joseph Priestley’s birthday falls on March 13th. If this assignment happens to coincide with that date, so much the better, but a celebration could be incorporated regardless of the date. Priestley could be called father of the soft drink. He noted that dissolving CO2 in water produced a pleasant sweet-tart effect.

Assign a quiz on acids, bases, and equilibrium to be given on day 25.

Day 24

EQ: How do catalysts affect chemical reaction systems? Understanding: Chemical reactions are affected by the physical conditions of the system, including energy, temperature, concentration, and solubility, and by the addition of a catalyst. The concept of equilibrium can be applied to physical systems, solutions, and gases, as well as to chemical systems such as acids. Specific understanding: • The activation energy must be overcome in order for a chemical reaction to occur, but

may be lowered by using a catalyst. Today demonstrate the difference in reactions with and without catalysts. Students generate oxygen by the decomposition of H2O2,.both with and without the catalyst, manganese dioxide, and compare the rates. Teacher note: There are numerous versions of this lab ranging from very basic to fairly technical. Check lab manuals for a version that fits time and needs of you class. Some micro scale lab books have an easy-to-set-up version of this lab. Debrief lab with a discussion of activation energy using energy diagrams for endothermic and exothermic reactions and the action of a catalyst relative to the energy diagram.


Day 25

EQ: How would you use test an antacid to determine its effectiveness? EQ: How can an antacid change the pH in your stomach? Understanding: The concept of equilibrium can be applied to physical systems, solutions, and gases, as well as to chemical systems such as acids. Specific Understandings:

• Typical acids and bases are solutions that contain an excess of either hydronium ions(acids) or hydroxide ions (bases).


Introduce and explain this lab. Use one of the versions for testing antacid tablets found in various laboratory manuals or on the web. Have students carry out the lab, collect data, and then make a decision about which antacid tablet “works” best and under what conditions. Students will write up their lab data; as an additional way for them to show their understanding, they can also create an info-mercial promoting the properties of their chosen antacid. These could be print advertisements or commercial skits. Teacher Note: This lab could be extended into a culminating task for this unit. If you choose to do this, use the rubric, Effectiveness of an Antacid Determining the Effectiveness of an Antacid in the appendix of this unit.


Day 26 Antacid commercials are presented today.

Day 27

EQ: How can the combined understandings gained in this unit explain the chemistry of a soft drink? Activate this lesson with the aquarium equilibrium demonstration. Students will compare the results of the different aquarium rounds and apply the principles of equilibrium to their observations. Priestley‘s Birthday Party: Essays for Priestley’s Birthday Party are due today. Arrange students in groups of five, and assign each student one of the participants in the “party”. Give students about five minutes to prepare, using their essay for reference. Then have each group act out the scenario described on Day 23.

Web Resources (optional) http://www.harcourtschool.com/activity/states_of_matter/, (Kinetic Theory of gases only) http://www.falstad.com/gas/, (Kinetic Theory with velocity) http://zebu.uoregon.edu/2000/ph102/ex2.html http://public.lanl.gov/alp/plasma/ubiquitous.html (Plasma) http://www.ornl.gov/sci/fed/Theory/tt/ttmcp/plasma.htm (Four states of matter graphic) http://fusioned.gat.com/images/pdf/Plasma_4th%20State_of_Matter.pdf http://www.science.uwaterloo.ca/~cchieh/cact/c123/heating.html (description of heating curve) http://www.dlt.ncssm.edu/TIGER/Flash/phase/HeatingCurve.html (graphic of water & heating curve) http://netcamp.prn.bc.ca/nuggets/heatingcurve.swf (graphic heating curve) http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf http://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-melts-ice.shtml http://www.chm.davidson.edu/ChemistryApplets/GasLaws/CharlesLaw.html http://www.programurl.com/ebas.htm http://www.trinityfiles.com/soft/Education/Science/chemcalcs.htm http://www.geocities.com/tjachem/ http://gemini.tntech.edu/~snorthrup/chem111/tutorials/chap3b/start.html

Additional Elements Sample List of Appropriate Resources (optional)

Appendix of Learning and Performance Tasks for Unit Exploring Systems: Reactions and Conditions

Brainstorming Activity 1. Ask students to brainstorm in their groups and come up with three systems per group. 2. List systems on the board. Have students discuss similarities and differences. From this activity, have the students develop a definition of “system”. Teaching Strategies for systems

1. Have students summarize in writing what a system is. Then introduce the concept of open and closed systems. 2. Locate transparencies in most resource kits of systems and apply the terms system, closed system and open system. (Solar, nuclear power plant, circulatory, respiratory, calorimeter, electrical circuit, dry cell battery, wet cell) Example: http://science.howstuffworks.com/nuclear-power.htm

Power plant drawing courtesy Nuclear Institute

Teaching Note: The symbol for heat is ΔH and the units can be calories or Joules. When ΔH is positive, it means heat is absorbed into the system and is therefore an indication of an endothermic process. When ΔH is negative, it means heat is released from the system and is therefore and indication of an exothermic process

This is an open system because it is okay if this water leaks out of the pipes into the atmosphere. None of this water should be radioactive.

This is a closed system because the water inside it is radioactive and should not be allowed to leak into the atmosphere.

Reinforcing systems The students will choose a system to research and report on. The report should explain how the system works. Parts and interactions should be identified. Energy changes should be explained. Teacher notes: Divide students into teams. Give them an example of a system from the list below or any other systems that would be appropriate for local students. Provide internet access or resource materials for research. This assignment could be given as homework. Students could be given options on their product if time permits. An example rubric follows. Remember to create all rubrics based on the elements addressed in the task. Present the rubric at the time the assignment is explained to the students. Some Examples: Closed systems: chocolate chip cookies, coolant component of home air conditioning, steam component of nuclear-powered steam plant, global positioning system (GPS), blood circulatory, radiator, gasoline or brake system on a car or motorcycle. Open systems: solar system (depends on criteria), air duct system of home air conditioning, baseball game, steam component of coal-fired steam plant

System ___________________________________

Category Expert Practitioner Apprentice Novice Self-evaluation

(1 to 4)

Teacher evaluation and

comment

Problem Student(s) produced a thoughtful, creative discussion on a system that engaged them in challenging or provocative research.

Student(s) produced a focused discussion on a system involving them in challenging research.

Student(s) constructed a discussion based on readily available answers.

Student(s) relied on teacher-generated questions or their discussion was superficial.

Information seeking/selecting and evaluating

Student(s) gathered information from a variety (3 or more) of quality electronic and print sources.

Student(s) gathered information from a variety (2 or more) of relevant sources: print and electronic.

Student(s) used information from one source with no evidence of a search for selecting other quality resources.

Student(s) gathered information that lacked relevance, quality, depth and balance, or did not document information.

Synthesis Circle One: Power Point Oral presentation Paper

The product logically and creatively, incorporates the information from the variety of quality sources.

The product is logically organized and has good connections of the ideas.

The product has some organization of the information .but does not clearly incorporate all the needed information.

The product lacks key information or lacks organization of this information..

Documentation Student(s) correctly cited all sources, including visuals, sounds, and animations. Product is essentially error-free.

Student(s) cited all sources, including visuals, sounds, and animations. There are minimal errors.

Student(s) cited sources but there are significant errors..

Student(s) did not cite all sources. Plagiarism is a concern here.

Georgia Department of Education Kathy Cox, State Superintendent of Schools

GeorgiaStandards.Org

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Δ H of adding water to anhydrous CuSO4

Hydrated copper (II) sulfate, CuSO4 ⋅5H2O, is a stable crystalline compound. This stability is related to the water molecules that are associated with the compound. If CuSO4 ⋅5H2O is heated, the water molecules will separate from the compound and evaporate into the atmosphere. It is then called anhydrous CuSO4. The name can be analyzed from its parts: the Greek prefix, a- or an-, means “without” and hydrous refers to water, Since anhydrous CuSO4 is less stable than the hydrated version, much of the energy used in the heating process is used by the compound to maintain the unstable state. Any energy exchange within the system, chemical or physical, can be measured because the necessary physical constants of water are known. PURPOSE: The purpose of this lab is to measure the heat energy liberated as the anhydrous form becomes hydrated. The container (environment) for this lab will be a calorimeter. The system in this lab is the anhydrous CuSO4. MATERIALS: anhydrous CuSO4, 250 mL beaker*, graduated cylinder, thermometer, 400 mL beaker*, 2 stirring rods *Use a bomb calorimeter if available PROCEDURE: 1. Obtain a dry 250 mL beaker. (The beaker must be completely dry.) Add exactly 3.00 g of

anhydrous CuSO4 evenly to the bottom of the beaker. 2. Measure carefully 200.00 mL of water and add it to the 400 mL beaker. 3. Accurately measure 1.69 g H2O. 4. Place the thermometer and one stirring rod into the water and place the other stirring rod into the

beaker with the anhydrous CuSO4. Record the temperature of the water. Place the small beaker into the 400 mL beaker and hold it down.

5. Carefully add the 1.69 g of water to the anhydrous CuSO4 and stir constantly. Record the highest temperature observed on the thermometer. Once the temperature starts to drop, the data collection portion of the lab is over.

6. Properly dispose of all chemicals and clean all glassware. DATA: Develop an appropriate table for data collection. Data analysis: The concept of an exothermic change was demonstrated. Calculate the amount of heat released from the anhydrous CuSO4 and absorbed by the water in the outer part of the calorimeter. Use the equation: ΔH = massH20 X ΔT X Cp. The Cp of water is 4.184 J/goC. Research the value for the heat of hydration of CuSO4. From these two values, calculate the percent error in your experiment. CONCLUSION: Complete a lab report that incorporates all criteria on the rubric.

Do you Understand? (To be turned in the day of the lab.) Category Expert Practitioner Apprentice Novice Score



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Data Data is accurately recorded in a data table that is logically organized , easy to interpret, and displays all necessary data.

Data is recorded in an organized data table with all necessary data.

Organized data table is present, but data is either incomplete or difficult to interpret.

Data is present but is not organized in a data table.

ΔH Student(s) uses the sign convention and the units properly through the lab.

Student(s) uses the sign convention and the units properly in most cases in the lab.

Student(s) uses the sign convention and the units incorrectly in some cases in the lab.

Student(s) did not use the sign convention and the units properly.

% error Student(s) correctly calculated the % error with the proper number of significant digits.

Student(s) had an error in either the % error or the number of significant digits.

Student(s) had an error in both the % error and the number of significant digits.

Student(s) did not report the % error.

System Student(s) analyzed the environment and the system and the possible source of the % error.

Student(s) analyzed the system and the possible source of the % error.

Student(s) did not fully explain the system in this lab or give a possible source of the % error.

Student(s) did not explain the system in this lab and did not give a possible source of the % error.

ΔH Process Student(s) accurately analyzed the endothermic and exothermic and identified which process was observed in this lab.

Student(s) accurately analyzed the difference in endothermic vs. exothermic.

Student(s) analysis or discussion of endothermic vs. exothermic is inaccurate.

Student(s) did not discuss endothermic vs. exothermic.



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Endothermic/Exothermic

Most processes are either endothermic or exothermic. Endo- is Greek prefix which means within while exo- is a Greek prefix which means out of. Therm- has origins in both Latin and Greek and generally is associated with heat. An exothermic process releases heat, and causes the temperature of the immediate surroundings to rise. An endothermic process absorbs heat and cools the surroundings. When you are trying to determine if a process is endothermic or exothermic, think of how the process affects the surroundings. For example, the melting of snow is an endothermic process. In the solid form, snow flakes have a regular shape with six points. As the snow melts, the sun's heat energy is used to cause water molecules to move around as the kinetic energy is increased. Because the snow flake has absorbed heat from the surrounding area, melting of snow flakes is an endothermic process. Objectives: In this activity, you will learn to recognize endothermic and exothermic processes within a system. Decide if the process is endothermic or exothermic and explain your rationale. PROCESS ENDO OR EXO? EXPLANATION making ice cubes condensation of rain droplets from water vapor

sublimation of frost to water vapor mixing water and strong acids formation of snow in clouds candle flame melting ice cubes evaporation of alcohol breaking down sugar molecules mixing water with an anhydrous salt making an anhydrous salt from a hydrate

nuclear fission rusting iron burning sugar cooking an egg producing sugar by photosynthesis baking cookies Extension:



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Language Teaching Strategies: Interactive word wall: Let the students make the words with a graphic for the word wall from a teacher-made list. Use the words from the language list for this unit and add others such as crystalline solid, amorphous solid, unit cell, lattice, lattice energy, cubic, metallic solid, ductile, malleable, X-ray diffraction, Buckyball. The words can be illustrated on panels that may be inserted on the room ceiling tiles, or as a border around the top edge of the classroom. The panel should include the word, and a labeled illustration that shows the importance of the word to the unit. Set other requirements as appropriate. Example:

Word Wall Activities Word walls should be an interactive, living instructional strategy. The following strategies may be a good place to start. Students should be encouraged to become an active part of the construction and maintenance of the wall. 1. Let the students make the words for the word wall from a teacher-made list. As an alternative, allow students to make the words (possibly with a graphic) after introducing the material. 2. Post words as they are introduced 3. Use words as Bell ringers/tickets out the door = have students define or use in a sentence 4. Rearrange words throughout the unit to show relationships. 5. Leave areas blank or cover up words to allow student to predict new ones or show prior knowledge. 6. Remove words from wall and pass them out to students. Then have them brainstorm with discussion regarding that word. 7. Utilize the ceiling as a word wall.

Heating curve of water A heating curve or cooling curve is a plot of temperature verses time for a substance where energy is added at a constant rate. Every pure substance has a characteristic heating curve that is consistent with the substance’s physical properties of melting and boiling points.

Buckyball



27

Purpose: To collect sufficient data to plot a heating curve and to analyze the energy events for each segment of the curve. Materials: 250 mL beaker heat source stirring rod ice thermometer Watch with second hand Procedure: 1. Place 100 g of ice and the thermometer in the 250 mL beaker. Adjust the heating device to a

moderate setting. (Do not adjust the flame or the hot plate once you begin the heating.) 2. Record the temperature of the ice and place the beaker on the heating device. Record the

temperature every 30 seconds until the water has boiled for 1 minute. Constantly stir the water between readings.

3. Construct a graph of temperature vs. time where time is the independent variable. Use a spreadsheet program when possible.

Analysis: Describe the energy changes that occurred in the water. Explain why the slope on the graph is not a straight line. Data Table:

Time

Temp

Do you Understand? (To be turned in the day of the lab.) Category Expert Practitioner Apprentice Novice Score

X-axis Student labeled the axis with the correct variable name and unit and assigned reasonable values to the grid lines.

Student had an error on either variable name, or unit values for grid lines

Student had errors on both the variable name and the unit values for grid lines..

Student did not label the axis with a variable name and unit. Student did not give the grid lines a value.

Y-axis Student labeled the axis with the correct variable name and unit and assigned reasonable values to the grid lines.

Student had an error on either variable name, or unit values for grid lines

Student had errors on both the variable name and the unit values for grid lines..

Student did not label the axis with a variable name and unit. Student did not give the grid lines a value.

Plotted Student correctly Student correctly Student had more Student had more than



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Performance Assessment: Heating curve for Lauric Acid Lauric acid is a fatty acid with structural formula CH3(CH2)10COOH. It is an organic acid and has a very low toxicity. It is the main acid in coconut oil and is believed to have antimicrobial properties. Lauric acid is slightly irritating to mucous membranes, but is used in many soaps and shampoos.

You are the supervising chemist over two bench chemists for the Research and Development Department of the local shampoo manufacturer. In the process of making shampoo it is imperative that the shampoo engineers know the melting point and at least twenty degrees at which it exists as a liquid. The easiest method for the laboratory staff to determine this information is by producing a heating curve. Your staff has already produced the heating curve for water, but the procedure will be a little different. The lauric acid will be in a test tube. The thermometer can be placed directly into the

points & line

plotted all data points and drew the best-fit line.

plotted all data points but did not draw the best-fit line.

than 3 errors when plotting the data points but drew a best-fit line.

3 errors in plotting the data points and did not draw a best-fit line.

Properties for 4 line segments

Student accurately described the physical state of water on each line segment.

Student accurately described the physical state of water on 3 of the 4 line segments.

Student accurately described the physical state of water on 1 of the 4 line segments.

Student did not describe or inaccurately described the physical state of water on all 4 line segments.

Events along each line

Student accurately described the physical changes occurring to the water on each line segment.

Student accurately described the physical changes occurring to the water on 3 of 4 line segments.

Student accurately described the physical changes occurring to the water on 1 of 4 line segments.

Student did not describe or inaccurately described the physical changes occurring to the water on all 4 line segments.



29

lauric acid, but the test tube with the Lauric Acid must be placed in a water bath. Your laboratory uses a 400-mL beaker filled with water for its water bath. You and your staff must have a handwritten or typed proposed procedure for the task to serve as a security pass into the laboratory. Notes are allowed if you think your staff may need them. Each person’s procedure will be scrutinized for safety hazards, but not for sequential lab procedures. You and your team must decide which procedure to use. You will have 90 minutes to collect data, produce the heating curve and a written (or word processed) explanation about the curve for the engineers. Use the rubric when completing this performance task. Teacher Note: Construct and provide rubric to students at time the assignment is given.

Specific Heat Capacity

Specific heat capacity, sometimes called specific heat (Symbol: Cp), is the measure of the heat energy needed to raise the temperature of a specific quantity of a substance by one degree of Celsius. Specific heat capacity has been measured for pure chemical elements such as lead and copper, compounds such as water or alcohol, and alloys such as brass. Imagine living in 1883 when Standard Sanitary Manufacturing Company and Kohler Company began producing cast iron bathtubs. An advertisement for an early Kohler tub stated that the "horse trough/hog scalder, when furnished with four legs will serve as a bathtub." When a person decided to take a bath, the water would be drawn from a well or from the river and heated over a fire. A person could easily get scalded in a bathtub. How would you cool the water if it were too hot? Of course, you would add some cooler water. To get a bath at the right temperature, the bather was applying the concept of specific heat.

Purpose: To explore and characterize the heat capacity of given liquids and solids s: hot and cold water 1 colorless unknown liquid hot water

thermometer 2 solids graduated cylinder balance

Procedure: To start this inquiry, obtain two equal masses of water. One should be hot and other cold. Design a way to find the relative heat capacity for the other substances. Determine which one has the highest heat capacity. Which one is lowest? Write down your procedure along with your data. Using your procedure see if you can repeat your findings. If you cannot, revise your procedure and try again.



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Heating curve for Water

Heat added

Tem

p (o

C

Heating Curve/Calorimetry Quiz

1. Number the line segments 1-5 beginning on the left side of the graph.

2. Add numerical values to the grids lines for the Y-axis.

3. On which line segments would you find the melting point? _____ boiling point? _____

4. Why is line segment 4 longer than line segment 2?

5. On a heating curve explain the significance of +ΔH and -ΔH. 6. Describe or draw a picture of a calorimeter that is made of a foam coffee cup, a test tube containing copper shot, a thermometer and some water. If you draw the picture, be sure to label all items. 7. Describe what happens when two bodies of matter at different temperatures are brought together? Consider the bodies could be identical or different.



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CONCEPTR QUIZ – Systems, Energy, Phase diagram 1. Sketch the graph of a process with a ΔH of 120 kJ/mole. 2. Alternative: http://www.sciencegeek.net/Chemistry/taters/energydiagram.htm Students should answer the questions at the end.

3. Giving reference to the phase diagram of water, describe (1) what occurs inside a pressure cooker and why food cooks faster and (2) why water boils at 68oC instead of 100 oC on top of Mt Everest. 4. Fill in the chart. PROCESS ENDO OR EXO? EXPLANATION melting ice cubes Sublimation of carbon dioxide Burning wood Oxidation of magnesium



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Rate of Solution Activating Strategy Notes to teacher: This activity can be done as an inquiry. Have students work in small groups of two or three. Determine the mass of one sugar cube. Make the mass of all samples of granular sugar and ground sugar equal to that of the sugar cube. The water temperatures are not critical since this is an inquiry, and students will not be able to control the temperature during the dissolving process. However, students should begin with the water temperatures as close as possible to those indicated in their instructions. Provide water on a hot plate at 100o C, an ice water bath, and room temperature water. From these water sources students can adjust their water to the required temperatures before adding the sugar. To expedite the activity, pre-weigh the samples of sugar. The teacher should control the stirring by saying start and stop each time the samples are to be stirred. Materials (per group): beaker, stirring rod, stopwatch, sugar samples and water Procedure for teacher: 1. Prepare sugar cubes, granular sugar, and grind some sugar into a fine powder (Do not used “powered sugar.) 2. Have water samples at approximately 0 oC, 20 oC, 50 oC, and 100 oC 3. Assign each group a different set up: This would be 12 groups. You could duplicate some set-ups if you have more than twelve groups. sugar cubes at 0oC granular sugar at 0oC ground sugar at 0oC sugar cubes at 20oC granular sugar at 20oC ground sugar at 20oC sugar cubes at 50oC granular sugar at 50oC ground sugar at 50oC sugar cubes at 100oC granular sugar at 100oC ground sugar at 100oC 4. As an extension to the stirring aspect of this inquiry, set up a demonstration that is not stirred. To set up the demonstration put equal amounts of water at 20oC into three beakers. Place a sugar cube in beaker one, an equal mass of granular sugar in beaker two and an equal mass of ground sugar into beaker three. Record the initial time and the time of complete solvation. This data should be given to students for later discussion. Procedure for students: 1. Hypothesize which set of conditions will cause the sugar to dissolve fastest. Give your reasoning for this hypothesis. 2. Obtain your group’s assigned set-up of sugar, water in beaker, stirring rod, and stopwatch. 3. Place sugar sample into water and start stopwatch at the same time Stir every 15 seconds for 3 seconds. Control this time closely. When sugar has completely dissolved record the time.. 4. Add your data to the class data table. 5. Analyze your data and the class data and determine whether it supports or refutes your hypothesis.



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6. Participate in the class discussion of the data and write up your lab report. 7. Clean up lab area.

Colligative Properties

Solvents have their own set of physical properties. For instance, the normal boiling point of water at STP is 100oC. If a solute is added to a solvent, the dynamics of the solvent particles change and the boiling point will change. Additionally, the change in boiling point is proportional to the number of particles dissolved in the solvent. The most common colligative properties are boiling point elevation, freezing point depression, osmotic pressure change and vapor pressure lowering. Purpose: To determine the new freezing point and boiling point of two solutions and calculate percent error. One solution will contain an ionic solute, and the other solution will contain a molecular solute. Materials:

1.00 Note to teacher: When you prepare the solutions, put your measured data on the label. Do not write the calculated molality on the container. Procedure: 1. In this lab insulate a coffee can with newspaper or paper towels to create a container for the ice

bath. 2. Measurements given in this lab are suggested values. For instance, where 100 mL of water is

required, you should attempt to get exactly 100.0 mL of water. However, if you get 98.6 mL of water, record the exact amount of the substance that you actually measured. In this example, you would record 98.6 mL. Assume DH20= 1.00 g/mL.

3. Place 100.0 mL of water in a beaker and heat. When the water has boiled for 1 minute, measure and record the temperature in a data table. Then pour this water out.

4. Obtain 30.0 mL of deionized water in a 125 mL flask. Determine the freezing point of this water. To accomplish this, place a layer of ice in the coffee can, set the flask in the can, and add ice and rock salt in layers around the flask. The temperature of this ice bath should be several degrees below 0o C. Gently stir the water in the flask. Using the thermometer record the temperature when ice crystals form in the flask.

5. Obtain 30.0 mL of solution #1 in a 125 mL flask. Calculate the molality of the solution from the data provided on the container. Determine the freezing point of this solution using the same procedure used for the deionized water.

6. Obtain 100 mL of solution #1 in a beaker. Heat the solution on a hot plate. If possible, use a hot plate that incorporates a magnetic stirrer and add the magnet bar to the solution. Otherwise, stir the solution with a stirring rod while heating. Record the temperature when the solution begins to boil.

7. Repeat steps 5 and 6 with solution # 2.

250-mL beaker rock salt thermometer Ice graduated cylinder 1-lb coffee can or 600 mL beaker 125-mL flask solution #1 =m KNO3 heat source solution #2 = 1.00 m C12H22O11



34

Data:

Actual Temperature

(oC)

molality Calculated Temperature

(oC )

Constant % error

L1 Boiling water

L2 Freezing water

L3 Solution #1 Freezing point KNO3

-1.86 o Cm

L4 Boiling KNO3 0.51 o Cm

L5 Solution #2 Freezing sucrose

-1.86 o Cm

L6 Boiling sucrose 0.51 mCo

Analyze the experimental data and compare to the calculated temperatures. Calculate the percent error. For extensions of this lab, refer to various laboratory manuals, or websites. For example: http://chemweb.calpoly.edu/chem/125/125LabExp/FPDepresson/FPDProc.html http://www.dlt.ncssm.edu/core/c12.htm

The Life of a Snowflake Performance Task In this unit you have learned about systems, endothermic and exothermic processes, states of matter specific heat, solvation, molality and colligative properties. We will discuss the behavior of gases in the next few days. Your task: Trace the progression of a snow flake from a cloud, through precipitation, onto a road surface that has been salted by the transportation department, and evaporation back into the cloud. Include energy flow through phase changes, temperature changes, solvation, colligative properties, and gas laws. For the purpose of this assignment, assume this snow flake is in a closed system that encompasses a particular volume of atmosphere and an area of land. Work individually or in groups of 3 or 4, as determined by the teacher. Project format may be a multimedia presentation, tri-fold project board, paper, or video. The length of the project is not as important as the content. There will be a fishbowl discussion after the presentations. Each student will volunteer for a panel, with each panel covering a different aspect covered by this assignment. The teacher will ask each panel questions about their topic.

Teacher Note: A fishbowl discussion allows students to demonstrate their understanding about a particular topic, discuss this understanding in front of an audience, and learn from their peers. Prepare rubrics for the project and for the fishbowl discussion.



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Cartesian Diver

Cartesian is a term that was named after René Descartes (1596-1650), a French scientist, mathematician, and philosopher. He laid the foundations of analytical geometry, algebra, and other subjects such as buoyancy and pressure. Descartes gave us the x-y coordinate system because he said that a point in a plane could be completely determined if its distances, say x and y, from two axes drawn at right angles in the plane were given.

Purpose: Explain the rise and fall of a Cartesian diver in a closed system. Materials: 20 oz soda bottle, plastic pipette, washer Procedure:

1. Observe the teacher’s Cartesian diver. 2. Make your own Cartesian diver system so that all members of your group can make the pipette

dive to the bottom of the bottle. 3. Using as many principles as necessary, explain the behaviors within the system.

Charles’ Law Activity In the mid-1700’s a French physicist, Jacques Alexandre Charles, observed that the volume of a gas varies in proportion to its temperature, if the pressure is held constant. If pressure is held constant, volume and temperature data collected and a plot of these data is generated, “classical” (non-quantum) absolute zero can be determined by extrapolation to be about -273 oC or 0K. William Thomson (Lord Kelvin) invented the Kelvin scale in 1848 with absolute zero being the lowest point on the scale or the point at which all matter stops moving and below which the temperature cannot be lowered. Modern calculations place this temperature at-273.18° C.

Purpose: To observe the effects of temperature change on an unfixed volume of air. Materials: syringe ring stand and clamp 2-1000 mL beakers

thermometer heating device

Procedure:

1. Set up a system to heat 600 mL of water in the beaker and to suspend the thermometer in the water. In the other beaker prepare an ice bath.

2. Pull the piston out to establish a volume of air in the syringe. Record the volume and room temperature. Cap off the open end and turn the piston to overcome any frictional forces between the piston and cylinder.

3. Lower the syringe into the beaker of water and begin heating the water. 4. One the temperature has reached 50 oC, record the volume and exact temperature. 5. Continue heating and record the volume and temperature in 5 oC increments. The last

recording should be at 100 oC.



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6. Place the thermometer into the ice bath. Carefully remove the syringe from the hot water and quickly place it into the ice bath. Record the volume at its lowest value. and temperature of the ice bath..

7. Graph the data with temperature as the independent variable and analyze. 8. Use the rubric provided by your teacher to guide the preparation of your lab report.

Bell-Ringer Quiz: Stoichiometry

Show all work.

Use dimensional analysis to solve the following problems. Express your answer in the proper number of significant digits and be sure to add the proper units. Circle your answer. Read each one carefully. How many moles of gallium chloride are formed by the reaction of 1.5 mol of HCl? What mass of gallium metal is required to completely react with the HCl?

2 Ga + 6 HCl → 2GaCl3 + 3H2 How many grams of carbon dioxide will be produced when 10.0 g of C3H8 are burned in excess oxygen?

C3H8 + 5O2 → 3CO2 + 4H2O How many moles of H2 are produced when excess chromium and 1.25 mol of H3PO4 are reacted? What mass of Cr is needed to produce 1.25 mol of H3PO4?

2Cr + 3H3PO4 → 3H2 + 2CrPO4



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Limiting Reactant Scenarios: See:

http://dbhs.wvusd.k12.ca.us/webdocs/Stoichiometry/Limiting-Reagent.html LIMITING REAGENT LAB Name__________________ 1. Write the balanced equation when HCl and NaOH combine in a double displacement reaction.. 2. Mass the evaporating dish and watch glass. Measure the mass of the NaOH pellets in the evaporating dish. Do not touch the pellets because they will severely burn your skin. Dissolve them in 15 mL of water in the evaporating dish. Mass of empty evaporating dish _________________g Mass of NaOH ________ g Mass of watch glass _________________g 3. Determine how many mL of HCl are needed to react completely with the measured mass of NaOH. There are 0.006002 moles HCl per mL. This is 6M HCl. Obtain the calculated amount of HCl plus 1 mL excess from the teacher. HCl obtained ____________ mL 4. Determine the theoretical yield of NaCl using stoichiometry. ____________ g 5. Pour the HCl into the NaOH solution that is in the evaporating dish. Stir thoroughly. Then boil off the water using the Bunsen burner. Do not bake the NaCl and use the watch glass to avoid spatter. Mass of evaporating dish + NaCl ___________ g Mass of empty evaporating dish ___________ g Mass of watch glass ___________ g Mass of NaCl (Actual yield) ___________ g 6. Calculate the percent yield of your product. ___________ %

% yield = actual

theoreticalx100%

Points to consider when writing LIMITING REAGENT Lab. 1. Why was the NaOH chosen over the HCl to be the limiting reagent? 2. Find out what precautions should be used when working with HCl and NaOH from the MSDS. Include any first aid treatments for accidents. 3. Why is it necessary to “heat to constant weight”? 4. What effect would adding too much excess reagent (HCl) have on the mass of the NaCl?



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Edible Indicators Objective: To develop a pH scale using a natural indicator and other indicators . Standard: SC7b Teacher note: The rationale for this lab design is found in the teacher note and discussion at the end of the lab. Materials: cabbage juice or other natural indicator, 0.1M HCl, 00.1M NaOH, 96 well plate, hydrion paper, other available indicators such as universal indicator, methyl orange, and phenolphthalein. Procedure: Pre-lab: This can be assigned as homework. Prior to lab day, prepare natural indicators. Obtain the colorful part of a plant, such as purple cabbage, purple onion, radish skins, purple grape skins, strong tea, red rose petals, or beet juice. Chop the plant material into tiny pieces and bring to a boil in a small amount of water. Reduce heat and simmer for at least 10 minutes to obtain a maximum amount of chemical extract and to concentrate the chemical as the water evaporates. Strain the liquid and store in a closed container in the refrigerator. About ½ cup of extract is more than enough for the lab. Prepare pipettes: Draw out the stems of 3 plastic pipettes to create micro-tips. This is done by firmly grasping the barrel in one hand and the stem in the other hand and pulling the stem. The stem will stretch to a narrower bore. Clip the barrel. Label the pipettes “acid”, “base”, and “water”. The well plate: In this procedure, every other row is skipped to make it easier to work with the reaction rows. Lab procedure: Use the acid pipette to add 10 drops of 0.1M HCl. to wells A1, C1, E1, and G1. Use the base pipette to add 10 drops of 0.01M NaOH to wells A12, C12, E12, and G12. Use the water pipette to fill all other wells in rows A, C, E, and G with 9 drops of water. Use the empty acid pipette to make a serial dilution of the acid. Take one drop of the HCl in well A1, add it to well A2. Return any acid remaining in the pipette back to A1. Then draw the contents of A2 up into the pipette to mix. Expel the contents back into A2. Use the empty pipette to transfer one drop from well A2 to well A3. Return any remaining acid back to A2. Draw up the contents of well A3 into the empty pipette to mix. Expel the mixture back into well A3. Continue this process until well A6 has been diluted. DO NOT add acid to well A7. Repeat this same process for rows C, E, and G. Use the empty base pipette to make a serial dilution of the NaOH, beginning with well A12 and working from A12 backwards to well A8. Use the same procedure for making and mixing the dilution that you used to dilute the acid. Do not add any NaOH to well A7. Repeat this process for rows C, E, and G. Once the serial dilutions are complete, add one drop of universal indicator to each well in row A. Add one drop of phenolphthalein to each well in row C. Add one drop of methyl orange to each well in row E. (Or choose another common indicator.) Add one drop of the home-made indicator to each well in row G.



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Record the data for each well. Answer these questions: 1. What is the significance of a serial dilution in relation to hydrogen ion concentration in this lab activity? 2. How much less is the H+ concentration in each well going from well 1 to 12? What is this factor? 3. What does a change of one unit mean on the pH scale? Teacher note and discussion: Once this process has been completed, it is time to discuss the meaning of the serial dilution in terms of acid/base concentrations. This lab has been designed so that the well number will actually match the pH of the solution in that well. This visual organizer helps students to understand the logarithmic and inverse nature of the pH scale. Draw a graphic organizer on the board that looks like the 12 wells of a well plate. (See below.) Work through this organizer with the students. In the row above each well number, write the concentration of the acid or base in that well. Note that the reason for beginning with 0.01 M NaOH is to compensate for there not being a well 13 to accommodate 0.1M NaOH. This set up was intentionally arranged to make it easy for the students to see the relationship between the exponent that shows the concentration of acid or base and the pH, which matches the well numbers in this lab. Be sure students understand that the pH scale is actually 0 to 14. Note that when set up like the data table below, it is easy for the student to see the correspondence between the well number, the concentrations in the wells, and the inverse of the log of the hydrogen ion concentration for that well. From this data the calculations for the OH- concentrations of each well can also be made.

10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 10-10 10-11 10-12

0. 1M HCl.

0.01M HCl.

0.001M HCl.

0.0001 M HCl.

0.00001 M HCl.

0.000001 M HCl.

H20 .0000001M H+ .0000001M OH-

0. 000001 M NaOH 0.00000001 M H+

0.00001 M NaOH .000000001 M H+

0.0001 M NaOH .0000000001 M H+

0.001 M NaOH .00000000001 M H+

0.01 M NaOH .000000000001 M H+

1 2 3 4 5 6 7 8 9 10 11 12

pH =1 pH =2 pH =3 pH =4 pH =5 pH =6 pH =7 pH =8 pH =9 pH =10 pH =11 pH =12



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Equilibrium Demonstration : Fill two aquaria to the same level. Have two volunteers oppose each other to scoop water from their aquarium to the aquarium of their opponent. Proceed in rounds as follows. Each round should run for one minute. Round One: Both students use cups that are the same size Round Two: Students use cups of different volumes Round Three: Have two students oppose one, all using the same size cups.

Round Four: Have two students oppose each other with equal size cups, but have a third student dipping water out of one aquarium into a waste bucket while the other two students continue their process.

Priestley’s Birthday Party Performance Assessment: Students imagine that Arrhenius, Bronsted and Lowry, Lewis, Haber, and Le Chatelier are gathered at Joseph Priestley’s birthday party, where Priestley is serving his new invention, soft drinks (carbonated water in sealed containers). Just imagine the conversation that would take place. Each man would want to explain those little fizzy bubbles from their own perspective. Research and write an essay comparing and contrasting each man’s ideas and what he would emphasize about acidity of the drink and/or the equilibrium of the drink before it was opened and after it was opened. Be prepared to take the part of any one of these men when called upon to do so on Day 28. Teacher Note: Provide the obvious props for the student conversations on Day 28: some soft drinks, cups, and ice.

Determining the Effectiveness of an Antacid An alternative culminating task Design and perform an experiment to determine the most effective antacid. Then create an info-mercial about your antacid. Format may be a video, a live skit, multimedia presentation, or a “print” advertisement such as a “billboard”. Rubric for antacid info-mercial

Category Expert Practitioner Apprentice Novice

As measured on a continuum

Self-assessment

Teacher assessment

& comments

Experimental design (written)

The experimental design was completely

The experimental design lacked a logical sequence

The experimental design could not be repeated as

The experimental design was missing.



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Scientific accuracy

The information came from experimental evidence and was accurate.

The information came from experimental evidence and was mostly accurate.

The information came from experimental evidence but is not accurate.

The information had no scientific basis.

Documentary Well organized, informative and entertaining.

Acceptably organized and informative

entertaining but needed more information and /or organization

Lacked organization, information and entertainment.

logical, accurate and repeatable.

but was accurate and repeatable.

written.

Indicator accuracy (data collection)

Choice of indicator was well thought out and all pH readings were recorded

pH was determined with an indicator and the data was recorded

An indicator was used, but there are some gaps in the data.

The cabbage indicator scale was completely incorrect.

Executive summary including sources (written)

Complete, and to the point analysis of the variables, the process, results and conclusions.

Missing some information, but gives a good overview of the experiment(s).

Describes the experiment(s) but is missing important information.

Does not explain the experimental work.

Sources Numerous applicable sources were used and cited correctly.

At least three sources were used and cited correctly, but some were not applicable.

Only one source was used and was cited incorrectly.

Sources were not given.

Persuasiveness

The film would persuade most people to use this antacid.

The film would persuade some people to use this antacid.

The film was somewhat persuasive.

The film had no persuasive language.

detailed unit

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