1. Purpose, Background, Data Collection & Processing Conclusion

2. Purpose and Background 1. Purpose a. Explain, in your own words, why we are conducting this lab b. What are we trying to find out? c. What information about hydrates do we need to know? d. Other than experimenting with hydrates, what will you be getting out of this lab? a. Looking for original thought other than just about hydrates

3. Data Collection and Processing 1. Include a raw data table a. Units for every number (or columns/rows) b. Complete descriptors for each measurement i. (empty test tube, etc.) c. Complete written observations (use your senses!) 2. Show all data processing (calculations) a. Use Equation Editor for the calculations b. Units on all numbers c. Show correct dimensional analysis (cancelling) 3. Show a results table a. Your results with units & percent error b. Results of other hydrates that you will be comparing to

4. Conclusion – Evidence Based CER 1. Concluding Statement a. What was your hydrate’s percent water? b. Of the three possible hydrates, which one do you think you have? 2. Support for your concluding statement a. Why did you conclude that you had that hydrate? b. Where did you get your information? a. Lab data as well as literature citations 3. Analysis – Assuming you did have that hydrate… a. Why do you have any percent error? b. Do your results show that you released too much or too little water from your hydrate? c. In performing the lab, what would have caused the error you found in (3a) and (3b)?

5. Example evidence based CER Claim: I believe that my unknown hydrate was SrCl 2 *5H 2 O. Evidence: My % water for my unknown was calculated to be 35.5% and the % hydrate for SrCl 2 *5H 2 O is 36.2%. Reasoning: A hydrate is a compound that has a constant composition (Hydrate Lab). This means that if I have a compound I will always have the same % of water, so if the % matches I have that hydrate.

6. Example evidence based CER Claim: I am very confident about my prediction Evidence: My % error was 1.9%, which means that there is a good chance I am correct with a very small error like that. Reasoning: No lab is perfect. I may not have heated the hydrate enough. If a hydrate is heated it loses its water (Prentice Hall Chemistry). If I didn’t heat it enough then it wouldn’t lose all of its water, so it is reasonable to think this is why my answer wasn’t perfect.

7. Example evidence based CER Claim: If I were going to do this lab again I would use a fresh sample. Evidence: Some hydrates will gain water when they are left out. This type of hydrate is called hydroscopic (Prentice Hall Chemistry). Reasoning: If Ms. Bjorklund left her samples out for 3 days and my sample was hydroscopic it could explain why my % error was very large. Evidence: I had a 13% error which suggests that too much water was released. Reasoning: If my sample was hydroscopic it would have more water in it than it should if it were left out exposed (Freeport Chemistry).