<p> Food for Thought</p><p>Grade Level 11 / 12 Subject: A.P. Chemistry (Chemistry) Prepared By: Gabriel Benjamin Wickizer & Duratio n:</p><p>Analyze Learners Overview & Purpose Education Standards Addressed (STEMcinnati US National Standards theme) From the AP Chemistry national definition: “AP Chemistry should meet the objectives of a good college general chemistry course. Students in such a course should attain a depth of understanding of fundamentals and a reasonable competence Energy modeling can in dealing with chemical problems. The course should contribute to the development of the students’ abilities to think be applied to food clearly and to express their ideas, orally and in writing, with clarity and logic.” preparation on a daily basis in Independence, Specific to this lesson are the following concepts: Kentucky and in Playa First Law of Thermodynamics, conservation, system, surroundings, heat, work, pv work, Joules, Calories, state function, Grande, Quiche, enthalpy Guatemala. Students will understand the Kentucky State Standards unique connection of SC-HS-1.1.8 mankind to energy Students will: through food  explain the importance of chemical reactions in a real-world context; preparation and the  justify conclusions using evidence/data from chemical reactions. societal impact of Chemical reactions (e.g., acids and bases, oxidation, combustion of fuels, rusting, tarnishing) occur all around us and in every cell in energy consumption. our bodies. These reactions may release or absorb energy. The intercultural SC-HS-4.6.1 emphasis of this lesson Students will: will enhance learning  explain the relationships and connections between matter, energy, living systems and the physical environment; as students relate to  give examples of conservation of matter and energy. examples from another As matter and energy flow through different organizational levels (e.g., cells, organs, organisms, communities) and between living culture and apply the systems and the physical environment, chemical elements are recombined in different ways. Each recombination results in storage and content to their own dissipation of energy into the environment as heat. Matter and energy are conserved in each change. context through analogous examples. SC-HS-4.6.7 They will engage in Students will: career practices used  explain real world applications of energy using information/data; by some mechanical  evaluate explanations of mechanical systems using current scientific knowledge about energy. and chemical engineers The universe becomes less orderly and less organized over time. Thus, the overall effect is that the energy is spread out uniformly. For example, in the operation of mechanical systems, the useful energy output is always less than the energy input; the difference appears to see how these as heat. professionals draw on thermodynamics in MA-HS-5.3.3 their every-day activity. Students will model, solve and graph first degree, two-variable equations and inequalities in real-world and mathematical problems. </p><p>MA-HS-1.2.1 Students will estimate solutions to problems with real numbers (including very large and very small quantities) in both real-world and mathematical problems, and use the estimations to check for reasonable computational results.</p><p>MA-HS-2.2.1 Students will continue to apply to both real-world and mathematical problems U.S. customary and metric systems of measurement. Teacher Guide Student Select Goals and Objectives Guide</p><p>Goals and Goals: Students Materials Needed Objectives Students will learn the conceptual model of energy flow stemming from the First Law expected to  Paper (Specify of Thermodynamics and the relationship of enthalpy to the energy of systems and have a  Pencil skills/information their surroundings. The energy system will provide a STEM motif for this working that will be  Bodum Vacuum learned.) multidimensional energy lesson. They will interact with real world applications of knowledge of Pot ($70) this model to discover energy systems and their surroundings. They will also scientific  Good, Fair Trade understand how energy analysis is conducted by career professionals such as notation and Coffee ($10) chemical engineers, health scientists, and mechanical engineers and how it be familiar  Pure, potable relates to the food they eat and the water (or coffee) they drink, while gaining with common water exposure to global society through the themes of energy flow and food. equation-  Bunsen Burner notation for  Corn Tortillas, Objectives: chemical broken into Students will classify the components of a wood-burning oven system (typical of rural reactions. quarters and Guatemala) and apply engineering taxonomy to an oven system typical of dried for two days Independence, Kentucky. in open air  Fresh corn Students will differentiate energy transformations involving chemical reactions from tortillas, refried those solely based on physical transformations. beans, salsa and rice with Students will analyze sources of error in a calorimetry test that estimates the energy packaging to content of food substances (beans, rice, and corn), justifying their reasoning with the show nutrition engineering concepts of enthalpy change and the Law of Energy Conservation. information ($15) Select Inquiry (Vacuum Pot, Pick-a-meal, and Taco Making Contest), Probing (Guatemalan  Thermal Instructio Kitchen & First Law Enthalpy Derivation), Discussion (Taco Making Contest and First (vacuum) pot for nal Law Enthalpy Derivation), Kinesthetic Activity (Vacuum Pot and Taco Making storing coffee, Strategie Contest), Spatial-Visual Presentation (Guatemalan Kitchen and First Law Enthalpy enough for 5- s – Derivation) ounces per student and 20 Information ounces for the (Give and/or instructor demonstrate necessary information)</p><p>Basic technology, such as a projector, will facilitate the introduction of intercultural Other Resources Utilize Technology material. Require Start First Day  Document Catch – Chemistry Needs Caffeine (2 minutes): Camera Learner Pass out cups of hot coffee (preferably from the thermal pot mentioned in the supply list) Participat  Internet capable ion Pre-Assessment -- Coffee’s Hot (5 minutes): computer Give the students the following questions on a small slip of paper along with their coffee  Projection screen Activity (explain that it is EXPECTED that they will not know the answers yet): If they take cream or (Describe the sugar, ask them to wait to add them until they have considered the questions. independent activity to reinforce Catch Extended – Vacuum Pot Demo (15 min.): this lesson) Firing up the vacuum pot, brew coffee for the class. Ask the question: “Where did the energy go?” and discuss the different components of this energy system (methane flame, glass pot, water, and air). Once it is clear that some of the heat energy has been used to expand and raise the heated water, hence being transformed into a form other than heat, this discussion has been successful. Move on to ensure ample time for the next section.</p><p>Main Activity – Guatemalan Kitchen (20 min.): Post the following words on the board and introduce them as essential vocabulary to this Half vs. other lesson: energy, system, chemical energy, energy source, heat, work, pressure-volume (pv) Half here? work. Define them on the board and draw the diagram (or use PowerPoint), asking the students to label HANDOUT-1 using the vocabulary provided. Take 5 minutes before filling in the blanks on the board and discussing the following questions: 1. “From what we have talked about, how can we define energy? 2. What units do you propose to define energy? Do you know any units used for energy?” 3. “What we are dealing with is one example of an energy system. What does ‘energy system’ mean?” </p><p>Formative Assessment – “Pick-a-Meal” (2 min.) Hand out worksheet and briefly explain the assignment</p><p>Review and Essential Questions (7 min.): 1. What is energy? 2. How does the definition of energy relate to energy units? 3. What is work? How can pressure-volume changes be classified as work? 4. What is an energy system? Classroom Start Second Day Catch – Get outa Here! (2 min.): Envelopes placed on the students’ desks that direct them to numbered stations in the lab next door. (See “Lab Station Instructions”). </p><p>Pre-Activity – Taco Making Contest (8 min.) Laboratory* Four groups of students will follow the instructions, making tacos during a three minute song. They will be judged quickly according to a formula on the instructor’s computer, reducing the work required for judging to simple data-entry (see Excel sheet attached).</p><p>Main Activity 1 – Taco Contest Follow-Up Discussion (10 min.) Still in the lab, hand out the sheet entitled “Lab Group Questions.” Assign each of four groups one question and ask them to present their answer. Emphasize what is correct and correct or modify what is incorrect. Following the discussion of question 4, invite the students back to the classroom to discuss a ‘new number called enthalpy.’ Return to the classroom. </p><p>Classroom Main Activity 2 – First Law Enthalpy Derivation (23 min.): 1. Relate the formal definition of internal energy (total potential and kinetic energy), then 2 enthalpy (internal energy and the work done by a system), writing the two and their symbols on the board. Write the expression for enthalpy in terms of ‘e’ and ‘pv’ as in Silberberg. 2. Select a volunteer to share their assignment from the night before, providing it contains a 6 chemical energy source. In that assignment, they have been asked to define an energy system. It is important that they correctly define it. 7 3. Use the Bunsen burner from the day before to remind the students of how energy can be released in chemical reactions like the combustion (redox) reaction they are observing. Write the methane redox formula on the board on one side. Ask for other examples of useful systems to consider—mentioning the universe as a system. Ask if the universe has surroundings. 4. Do the derivation included on the right side, prompting, “Tell me what is wrong with this 8 statement:” Make sure that the first or the second step becomes your platform to discuss the First Law of Thermodynamics in a formal sense. Discuss the assumptions required in a given step and remember to relate the energy released to chemical bonds broken. *Note: It is  System Energy Change = Total Energy Input + Total Energy Output How do we know this is true? What does this assume? Write the 1st Law of Thermodynamics: advisabl “Energy is neither created, nor destroyed” in the universe. e to  Enthalpy Change = Enthalpy Input + Enthalpy Output adapt  h = hinput + houtput this  h = ( einput +pvinput )+ ( eoutput + pvoutput )  h = e +pv) Thanks to lesson in  Or, h = u + pv “Where are we?” Show the students how the Methane Redox formula http://www.cedu.niu.e cases is a restatement of the final step of the derivation. du/scied/resources/sci encemisconceptions.h where tm the classroo m and lab are a decent distance Review and Essential Questions (6 min.): 1. What symbols correspond to each change? What units? 2. How does the First Law of Thermodynamics define the universe? 3. What is the indicator that takes both fundamental forms of energy into account?</p><p>Be Mindful of Common Misconceptions regarding Energy 1. Energy is truly lost in many energy transformations or things “use up” energy. 2. There is no relationship between matter and energy. 3. If energy is conserved, why are we running out of it? 4. Energy can be changed completely from one form to another (no energy losses). 5. Energy is confined to some particular origin, such as what we get from food or what the electric company sells.. 6. Energy is a “thing.” This is a fuzzy notion, probably because of the way we talk about newton-meters or Joules. It is difficult to imagine an “amount” of an abstraction. 7. The terms “energy” and “force” are interchangeable. From the non-scientific point of view, “work” is synonymous with “labor.” It is hard to convince someone that more “work” is probably being done playing football for one hour than studying an hour for a quiz.</p><p>Post-Assessment – Cream and Sugar (5 min.): Distribute an identical set of questions to the pre-assessment, explaining that this is to understand what they have learned. Ask them to add cream and sugar, or to at least consider the cup as if they had.</p><p>Error Analysis Assessment Assigned – Groups of 3-4 (as in Taco Making Contest) This will be part of a larger, calorimetry lab that will relate other new concepts, but the consideration of energy in calorimetry will come from this lesson. Evaluate Pre-assessment (Coffee’s Hot) based on the coffee-drinker’s categorizations of the Additional Notes (Assessm energy flow in the coffee-cup-table system. Questions are as follows: ent) 1. How do you define work? 2. Is the heat energy in your coffee doing any work? (Steps to check for 3. If your coffee holds 38 units of energy and I add cream, which has -8 units, student how many units of energy are left in my coffee? How about if I use the heat understanding) to do 20 units of work? 4. What single number might a thermo-chemist use to describe changes in the energy of the coffee cup system?</p><p>Formative Assessment: 1: Pick-a-Meal Assessment Individuals will pick a meal and diagram it during class. It must include a heat source and a food product. They will label the inputs as heat and work. See “Pick-a-Meal” handout.</p><p>Post-Assessment (Cream and Sugar?) Have the class repeat the analysis of their own coffee-cup system. See questions above.</p><p>Summative Final Assessment and Formative Assessment See handout – Students will analyze sources of error in the calorimetry lab which follows this lesson. The materials from the tacos will be studied in the lab to learn about basic concepts of calorimetry, but the content from this lesson will be required to conduct the error analysis and comprises a summative final assessment of the student’s progress. It also connects the material to the chemical engineering and health sciences through calorimetry. Author’s Reflection</p><p>In retrospect, this lesson will be dangerous to implement if ample time is not given for setup. The taco contest on the second day required about an hour of preparation time for cooking rice, portioning ingredients, etc. The coffee on the first day required pre-brew and time to grind coffee for the vacuum pot, lay out water ahead of time, and adjust a ring stand to the proper setting for the pot. The fun things about this lesson are also time intensive. That said, the first day was rather smooth. I believe that the meal diagram could be made to be more effective if the students had some more examples. My initial thought in this direction is to have some more examples, such as car engines, campfires, and air-conditioners diagramed in the same way as the Guatemalan kitchen. It would be quite important to spend much less time going over these, but they would emphasize the content. For the “Pick-a-Meal” assessment that the students take home, it will be important to take a grade. I intended this assignment as a simple measure of where students are—“so it doesn’t need a grade, right?” I feel that it would be best to make a rubric, hand that out along with the worksheet, and prepare the students to take it seriously. Even my very attentive AP Chemistry students seemed to rush through it far too quickly. It is intended to be a light load, so I would still suggest a very basic set of requirements for the rubric. The second day needs additional input in terms of linking the activity to real world engineering. The taco contest could carry a stronger theme of nutrition science and the needs our bodies have in relation to the ways we use energy. This might require re-apportioning the time of delivery in this lesson to three days. Then the lecture portion where enthalpy is introduced could be better linked to nutrition and calorimetry. This link will ameliorate many of the problems with disengagement during this portion. Dr. Kukreti also suggests breaking up the lecture with a short hands-on activity. I think the methane flame is precisely such a thing, but perhaps a candle for each student could achieve the same effect and allow the students to discuss the combustion process as an enthalpy change (as Dr. Manglik later suggested). In any case, getting the students to touch and taste the system again as they apply the concept of enthalpy to it seems important.</p><p>In summary, I suggest these specifics:  Gearing up the lesson with the proper prep-time (30 min. the first day and 1 hour the second)  Linking the taco contest more strongly to nutrition and use in the body, verbally and pictorially  Breaking up the enthalpy lecture with a hands-on view of combustion as an enthalpy change  Creating a rubric for the Pick-a-Meal assessment to formalize it  Diagramming more real-world systems to show briefly after the Guatemalan Kitchen example</p>