Sub-Zero — High School Sample Classroom TaskIntroductionChemical reactions can be described as endothermic or exothermic depending on whether energy is used orgiven off during a reaction. Practically, these types of reactions can be used as instant hot or cold packs at times when we need them, such as in hand warmers. In this task, students will demonstrate their knowledgeof chemical reactions and energy change during the reactions. They will use molecular models to diagram the change in the arrangement of atoms and number and types of bonds before and after reactions. Following experiments where they measure the change in temperature of the reactions, they create models showing the change in energy (bond energy and thermal energy) in addition to the changes in the chemical species and number and types of bonds. Finally, students compare theoretical values for the temperature change of the reaction (given different reactant amounts) with their measured values using graphs and equations for lines of best fit and make evidence-based claims for whether the reactions they tested would be useful in hand warmers given criteria related to safety and usability.Standards Bundle(Standards completely highlighted in bold are fully addressed by the task; where all parts of the standard are not addressed by the task, bolding represents the parts addressed.)CCSS-M MP.1 Make sense of problems and persevere in solving them.MP.2 Reason abstractly and quantitatively.MP.3 Make a viable argument and critique the reasoning of others.MP.4Model with mathematics.MP.6Attend to precision.HSN.Q.1Use units as a way to understand problems and to guide the solution of multi-stepproblems; choose and interpret units consistently in formulas; choose and interpret the scale and the origin in graphs and data displays.HSN.Q.2Define appropriate quantities for the purpose of descriptive modeling.HSN.Q.3Choose a level of accuracy appropriate to limitations on measurementwhen reporting quantities. HSA.CED.1Create equations and inequalitiesin one variable and use them to solve problems.Include equations arising from linearand quadratic functions,and simple rational and exponential functions.HSA.REI.3Solve linear equations and inequalitiesin one variable, including equations with coefficients represented by letters.HSS.ID.6Represent data on two quantitative variables on a scatter plot,and describe how the variables are related.HSS.ID.6aFit a function to the data; use functions fitted to data to solve problems in the context Version 2-published January 2015 Page 1 of 29View Creative Commons Attribution 4.0 Unported License at . Educators may use or adapt.
of the data.Use given functions or choose a function suggested by the context. Emphasizelinear, quadratic, and exponential models.