Chemistry Lab 8: Energy and Calorimetry This week, we will be virtually exploring energy and calorimetry- the process exchanging heat between substances. Equipment: This is a virtual lab- but list all of the equipment that we used “virtually” Problem: How do different substances heat up or cool off when combined in a calorimeter? Procedure: 1. Navigate to: https://media.pearsoncmg.com/bc/bc_0media_chem/chem_sim/calorimetry/Calor.php, 2. Read through the Overview and the Learning Outcomes, then click on Experiment and select “Run Demonstration”. 3. Read each step to help you answer questions below. 4. You will summarize the steps of each experiment and note the substances involved, and their temperatures before and after the experiment ends. Do this for each demo experiment: • Hot water to room temperature water • Hot metal to room temperature water • Compound to room temperature water • Mixing 2 solutions together 5. You should make a rough sketch of how the temperature changes during each of the 4 experiments (as shown in the graphs). Explain what is happening for each one. 6. When you have finished the 4 demonstration experiments, you will run one more on your own: • Select solids- ammonium nitrate, measure out 20g at 20°C (hit next) • Select liquids- water, measure out 100g at 20°C (hit next) • Hit start to run the experiment, sketch the graph and describe the changes in the solution that you made Questions: (Please make a separate section of your report to answer these in) 1. What is a calorimeter? 2. When adding hot water to room temperature water- which sample gains heat? How does this happen at the molecular level? 3. How is adding hot metal different from hot water- why do you think this is? 4. Is the enthalpy (∆H) of LiCl + H2O positive or negative- why? What kind of reaction would that be? 5. Write out the chemical equation for the reaction of HCl and NaOH- what type of reaction is this? 6. What kind of reaction happens when water and ammonium nitrate are mixed together? Would ∆H be positive or negative? Why? 7. If you repeated the experiment placing a hot piece of metal into water using a different metaldo you think it would heat the water in the same way as Cu did? How could you design an experiment to test the heat capacity of various metals? Try one and report your results.
