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Designing Exothermic and Endothermic Reactions (4 Favorites)

LAB in Classification of Reactions, Chemical Change, Heat, Temperature, Exothermic & Endothermic. Last updated November 5, 2018.


Summary

In this lab, students will design and test an experiment for producing either an endothermic or an exothermic reaction. The goal of the lab is for students to successfully construct a reproducible procedure for a reaction that either releases or absorbs thermal energy, and that can be supported with data.

Grade Level

Middle or high school

Objectives

By the end of this lab, students should be able to:

  • differentiate between an endothermic and exothermic reaction.
  • identify the expected temperature change associated with an endothermic and exothermic reaction.
  • design a valid procedure used to create an endothermic or exothermic reaction that can be used to replicate reliable results.

Chemistry Topics

  • Endothermic reactions
  • Exothermic reactions
  • Chemical Reactions

Time

Teacher Preparation: 20 minutes

Lesson: 50 minutes

Materials

  • Vinegar
  • Water
  • Baking Soda
  • Steel Wool
  • Plastic Cups
  • Thermometers
  • Graduated Cylinders
  • Timer
  • Laptops/tablets for individuals or groups

Safety

  • Always wear safety goggles when handling chemicals in the lab.
  • Students should wash their hands thoroughly before leaving the lab.
  • When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.

Teacher Notes

  • Endothermic reactions result in a temperature decrease. An endothermic reaction absorbs heat from the surrounding atmosphere or liquids.
  • Exothermic reactions result in a temperature increase. An exothermic reaction gives off heat as a byproduct of a chemical process.
  • It is essential that the students design, test and modify their own experiment. The teacher should simply facilitate the activity but allow the students to construct the experiment.
  • Water is not needed to create either an endothermic or exothermic reaction. It is provided simply as an extra resource.
  • Based on the supplies provided:
    • Combining vinegar and baking soda will result in an endothermic reaction which will have a lower temperature.
    • Combining vinegar and steel wool will result in an exothermic reaction which will have a higher temperature.
  • Teachers may want to limit the amount of materials given to each group, and also caution students to conduct their investigation on a small-scale, as not to waste materials.
  • This activity provides a real world connection for students by showing that it is vital to understand the process of designing, testing, and modifying an experiment. Also, that it is critical to write procedures in a way that can be carried out properly and will yield the same results.
  • Student written lab procedures can either be tested by the teacher for all to see or they can be exchanged with another group for testing accuracy and effectiveness. If you decide to do this, allow for additional class time.

For the Student

Background

Endothermic reactions result in a temperature decrease. An endothermic reaction absorbs heat from the surrounding atmosphere or liquids. Exothermic reactions result in a temperature increase. An exothermic reaction releases heat as a byproduct of a chemical process.

Objective

You will design and test a laboratory experiment using the materials given to create either an endothermic or an exothermic chemical reaction.

Materials

  • Vinegar
  • Water
  • Baking Soda
  • Steel Wool
  • 16 oz Plastic Cups
  • Thermometers
  • Graduated Cylinders
  • Timer
  • Laptops/tablets

Safety

  • Always wear safety goggles when handling chemicals in the lab.
  • Wash your hands thoroughly before leaving the lab.
  • Follow your teacher’s instructions for clean-up of your materials and dispose of any chemicals.

Procedure

  1. You will design and test a laboratory experiment using the materials given to create either an endothermic or an exothermic chemical reaction.
  2. With the given materials in mind, first construct a procedure, and then carry out the procedure, recording data as needed (temperature change). Finally, modify the procedure as needed. You may need to repeat these steps a number of times until you have successfully created a procedure that for an endothermic or exothermic reaction.
  3. You do not have to use all of the materials, and your final procedure may be different than other groups, this is expected.
  4. You will only design and test a procedure for creating an endothermic or an exothermic reaction, not both. You are not creating two different experiments.
  5. Your experiment must be designed to collect measurable data (temperature). See the example data table below for guidance.
  6. You must be able to replicate your own experimental procedures, and its results multiple times before you move on to step 7, which is documenting your experiment guidelines.
  7. After you have successfully created a procedure for an endothermic or exothermic reaction using a selection of the given materials, you will need to document the lab guidelines to be used by somebody else to carry out the experiment.
  8. Your lab guidelines should include a title, lab objectives, material list (including quantities), safety precautions, procedural steps, and data table. See the Lab Guidelines template for help and formatting.

Data (sample)

Test # Initial Temperature Final Temperature