Investigating Burning Ethanol

1. Investigating Burning Ethanol

2. Steps in Investigation • Initial prediction and explanation • Observations: Measurements of changes in mass and CO2 • Learning about 5 practices for describing chemical changes • Constructing an argument from evidence that combines claims, evidence, and reasoning

3. Steps in Investigation • Initial prediction and explanation • Observations: Measurements of changes in mass and CO2 • Learning about 5 practices for describing chemical changes • Constructing an argument from evidence that combines claims, evidence, and reasoning

4. In your own words…. • Explain what happens when ethanol burns. Try to include in your explanation: • All the materials (solids, liquids, and gases) that are changed when ethanol burns. These are called reactants. • All the materials that result from ethanol burning. These are called products. • Changes in energy: what happens to the chemical energy in the ethanol. • Predict changes that we will be able to measure

5. Use the Process Tool to Show Your Prediction and Explanation When ethanol burns, what happens to it and the things it needs to burn? Ethanol Ethanol burning After burning Before burning Predictions for change in mass

6. Steps in Investigation • Initial prediction and explanation • Observations: Measurements of changes in mass and CO2 • Learning about 5 practices for describing chemical changes • Constructing an argument from evidence that combines claims, evidence, and reasoning

7. A Question about BTB BTB (bromothymol blue) is an indicator that changes color when there is lots of carbon dioxide in the air. How could you figure out what color it changes?

8. Use the tables in your worksheet to record • Mass of ethanol before and after for BTB experiment • Color changes in BTB • Mass of ethanol before and after for soda lime experiment • Mass of soda lime before and after • Other observations you made • Possible problems with accurate measurement and how to make the measurements as accurate as possible.

9. Steps in Investigation • Initial prediction and explanation • Observations: Measurements of changes in mass and CO2 • Learning about 5 practices for describing chemical changes • Constructing an argument from evidence that combines claims, evidence, and reasoning

10. Five Practices for Finding Chemical Change in Life and Lifestyles

11. How did you use three practices to explain which materials will burn? • The materials practice: • Identifying organic and inorganic materials • The subsytems practice: • Identifying C-C and C-H bonds in molecules • The energy practice • Identifying materials with more chemical energy

12. Steps in Investigation • Initial prediction and explanation • Observations: Measurements of changes in mass and CO2 • Learning about 5 practices for describing chemical changes • Constructing an argument from evidence that combines claims, evidence, and reasoning

13. Claim, evidence, and reasoning • Claim: What is your revised explanation of what happens when alcohol burns, including reactants, products, and energy transformations? • Evidence: What observations and measurements support your claim? • Reasoning: How does the evidence support your claim?

14. Use the Process Tool to Show Your New Explanation When ethanol burns, what happens to it and the things it needs to burn? Ethanol Ethanol burning After burning Before burning Predictions for change in mass

15. Does your explanation conserve matter?

16. Does your explanation conserve mass?

17. Does your explanation conserve atoms?

18. Does your explanation conserve energy?

19. Evidence of CO2 in air from burning 4 minutes 8 minutes 10 minutes, with control