Day 2 of 3--Student Inquiry Regarding Endothermic and Exothermic Reactions: Carrying out a Student-Designed Investigation

Objective

SWBAT conduct an investigation of their own design and collect data in order to analyze that data as they seek to answer a specific question regarding endothermic and exothermic reactions.

Big Idea

Differing concentrations of reactants may (or may not) have measurable effect on heat flow; data collected during investigation may not lead to conclusive answers to initial questions.

Why This Lesson?

This lesson is Day 2 of a 3-day series.  The lesson before and lesson after can be found here:  Day 1 and Day 3.

At this point, students should have chosen a question that they will seek to answer through the inquiry process.  Today, students will be carrying out their investigations (already planned during Day 1) and collecting data.  Tomorrow, students will be analyzing their data to make conclusions and answer their focus question. Through this process, students are engaged in SEP 3 - Planning and Carrying Out InvestigationsSEP 1 - Asking Questions, SEP 4 - Analyzing and Interpreting Data, and SEP 5 - Using Mathematics and Computational Thinking.

Through their investigation, students will be working on developing their understanding of Crosscutting Concept XC-EM-HS-2: Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.  Students are also building their ability to meet Performance Expectation HS-PS3-1: Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

Pre-Lab Discussion

10 minutes

I remind students to wear safety goggles during investigations and direct one person from each group to get enough goggles for the entire group.  I also point out the materials that are available and show students where to find each one.  I tell students to collect the materials they will need based on their written procedures and to make an equipment basket for their group.

I explain that all data needs to be collected today so that we can analyze it during the next class meeting.  I also field any questions that students might have about the investigation process, but I will not give recommendations for specific procedure steps.  As difficult as it is to hold back, I want my students to have the opportunity of designing a less-than-successful investigation so that they learn what to do better the next time.  Often we learn far more from our mistakes than from our successes!

I handout Chemistry - Designing an Investigation Endo Exo procedure write up, one to each group, so that they can neatly document their investigation and data as they collect it.

Small Group Investigations

45 minutes

Students have the rest of our class time to conduct the data collecting phase of their investigation.  It is important that all data gets collected today so that we can spend the entire time tomorrow analyzing it and drawing conclusions (even if the conclusion is specific improvements to make for the next time!).

Student Samples:

Sample #1

Sample #2

Sample #3

In all of these samples, more trials would certainly be better!