Notes
Teaching Ideas and Suggestions
Thermochemistry represents one more opportunity within the chemistry curriculum to revisit the importance of the coefficients in a balanced chemical equation. The components define the relationship between the moles of reactants and products and (in the case of thermochemical equations) the amount of energy released or absorbed by the system during the reaction. This Concept Builder provides three scaffolded activities to lead students through the process of implementing an understanding of stoichiometric relationships that pertain to energy. There are a total of 16 multi-part questions that have been organized into three levels of difficulty.
In the Apprentice Difficulty Level, students complete five sentences, each of which has a numerical blank. The sentences start simple (real simple) and increase in difficulty. The emphasis is on gaining some comfort with the use of the equation to solve for an unknown. In the Master Difficulty Level, students must complete a 5-row table with 2-3 blanks per row. Students must work with the mass-mole-kJ relationships to complete the table. The numbers presented in the table are mostly nice. That is, they tend to be whole number multiples of the coefficients or the molar mass.The thermochemical equation represents the combustion of propane. The coefficients are relatively simple compared to the Wizard Level. In the Wizard Difficulty Level, students must complete a 5-row table with 2-3 blanks per row. The thermochemical equation represents the combustion of butane; the coefficients are immediately more complicated than that of the Master Level. And the numbers presented in the table are no longer nice whole number multiples of the coefficients.
The questions are shown on a separate page (viewable by logged-in teachers only). Teachers are encouraged to view the questions in order to judge which activities are most appropriate for their classes and what level of preparation would be required. We recommend doing the activities in order. There is no redundancy in the actvitiies. While they are independent activities, they have been designed to be scaffolded such that one activity builds on the confidence that was derived from the previous activity.
Our Concept Builders typically utilize a variety of strategies to make each student's experience different. The main strategy employed here is to provide multiple tables for each level. A table is selected at random and presented to the student. This reduces the likelihood that two side-by-side students would have the same question.
Health Bar
We leave it to the discretion of individual teachers as to what they wish to do with the Health rating information. We recognize that there will be some teachers who feel most comfortable with their students in simply requiring that a difficulty level be completed and trophy be earned. Other teachers may wish to require completion of a difficulty level with a minimum Health rating. For instance, such teachers may require that each difficulty level be completed with a 70% or higher Health rating. Still other teachers may tie the Health rating into a grade or allow a homework pass for completing an activity that exceeds a 90% Health rating. Decisions as to what to do with the Health rating are best left for individual teachers who know their students the best.
Task Tracker Notice: As of this writing we do not record Health Ratings in our Task Tracker database. It is for on-screen use only when used in the classroom in the presence of a teacher. The teacher can validated the Health Rating if desired.