We're going to be honest: we do Physics. That's why this is called The Physics Classroom website. And when we do the Teacher's Notes section for our Concept Builders, we typically have a lot to say ... and a lot of resources to point you to. We're not claiming to be ignorant of chemistry; we just don't have a lot of resources here at The Physics Classroom to point you to. And so this page is going to be a lot shorter than our usual page that accompanies our Physics Concept Builders. That's our honest confession.

Nearly all chemistry classes will devote some attention to the process of calorimetry as a means of determining the quantity of heat exchanged between the system and the surroundings for some type of process. It is not uncommon that several labs are performed that rely on the use of calorimetric methods. This Concept Builder focuses on the use of calorimetry and the Q = m•C•∆T equation. The Concept Builder consists of three higly scaffolded difficulty levels. Each difficulty level consists of a single multi-part, numerical question. Answers are numerical in nature and result (in part) from the use of the Q = m•C•∆T equation. In all cases, a water calorimeter is used. In preparing answers, we used a C value of 4.18 J/(g•°C). An error allowance of 2% is allowed so an extra digit is not going to make a difference. 

In the Apprentice Difficulty Level, students complete five sentences, each of which has a numerical blank. The sentences start simple (real simple) and quickly 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 two blanks per row. The added component that is assessed in this activity is the relationship between temperature change and the initial and final temperature; one blank in each row is devoted to this relationship and the other blank is related to the use of the Q = m•C•∆T equation.  In the Wizard Difficulty Level, students must complete a 5-row table with three blanks per row. The emphasis of this level is on using calorimetry measurements to determine an enthalpy change of a reaction.  Of the three blank cells in each row, one of targets the mass-mole relationship for the reactant. The molar mass is given in the problem statement (we have avoided using real reactants and simply resorted to providing a molar mass). The second relationship in this level is the Q-moles-∆H relationship. And finally, the third blank cell can be determined by the use of the Q = m•C•∆T equation.  


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 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. 
 

 

Students can complete as much of the table as they wish before checking their answers. And they can check their answers as many times as they wish. Feedback regarding the correctness of their answers is immediate and provided using a color-coding system. Correct answers are displayed in a table cell with a green background; these correct answers become locked and cannot be changed. Incorrect answers are displayed in a table cell with a red background. Each time students check their answers, the number of missed answers is determined. A running tally is kept of the number of misses. When a student accurately completes the table, a Health rating is displayed on the screen. The Health rating is dependent upon the number of misses. Formulas for computing the Health rating are discussed on a separate page. The Health rating is also displayed on the Main Menu screen for any completed difficulty level. A student can always repeat a difficulty level in order to improve their Health rating for that level. The best Health rating is always displayed on the Main Menu screen below the trophy for that difficulty level.

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.


 

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.