Title: Exothermic versus Endothermic Reac ons Abstract: (Wri en a er lab is completed) Background: DESCRIBE EXOTHERMIC AND ENDOTHERMIC REACTIONS AND PURPOSE Hypothesis:WRITE A HYPOTHESIS FOR THREE OF THE REACTIONS IN THE DATA TABLE Materials: ● ● ● ● ● ● ● ● ● ● ● ● Test tubes .1 M CH3COOH (ace c acid/Vinegar) H2O2 (Hydrogen peroxide) Calcium Chloride Yeast Borax NaHCO3 (Baking soda) H2O Thermometer Graph paper Goggles Disposable Pipe es Methods: 1. Wear appropriate safety materials (goggles and lab coat) 2. Gather all your materials 3. Set up your test tube rack as shown below: A = Baking Soda B = Calcium Chloride C = Yeast D = Borax E = Baking Soda F = Calcium Chloride G = Yeast H = Baking Soda I = Calcium Chloride J = Yeast + + + 4. Add 1-2 scoops of each of the DRY chemicals to the appropriate tubes (as shown above) 5. Using the disposable pipe e, slowly add ~5ml of water. DO NOT ADD TOO FAST. Add up to 4ml more if any solid remains. 6. Record any observa ons and final temperature in the data table 7. Repeat Step 5 and 6 but with Vinegar and then with Hydrogen Peroxide Results: Tube Solid Liquid A Water I Baking Soda CaCl2 Yeast Borax Baking Soda CaCl2 Yeast Baking Soda CaCl2 J Yeast B C D E F G H Water Water Water Vinegar Vinegar Vinegar Hydrogen Peroxide Hydrogen Peroxide Hydrogen Peroxide Ini al Final Temp Observa ons Temp Temp Diff Chem Rxn? Analysis: <BAR GRAPH OF TEMP VS SOLUTION COMBINATION> *Organize by solid LAB QUESTIONS: 1. Which of the reac ons was endothermic? How do you know? 2. Which of the reac ons was exothermic? How do you know? Conclusions: Two paragraphs (one restate purpose and hypothesis along with whether data proved/disproved and the second discuss how experiment could be improved and/or follow-up exp.)
