Full Name Partner’s Full Name Period # Baggy Lab – Causes of Observed Chemical Changes Purpose of the Lab: Determine which combinations of substances cause the changes observed when the following are combined: phenol red in water, calcium chloride (CaCl2), and sodium bicarbonate (NaHCO3) (Baking Soda. Hypothesis: An hypothesis is drafted using “If…then…because…” In this lab you will predict what causes each observed change using only “If…then…” Write your hypothesis below. Temperature Change: Gas Production: Color Change: Materials: Calcium Chlride (CaCl2) Sodium Bicarbonate (NaHCO3) Phenol red dye mixed with water Water Graduated Cylinder Measuring spoons Zip lock bags Goggles Student Info Purpose Procedure (Brief) Procedure (Complete) Procedure (Brief) Procedure Procedure A Begin with the overall reaction you saw during the demonstration using the following steps 1. Lay a zip-lock bag flat on a table 2. Place one teaspoon of calcium chloride in one area of the bag. 3. Place ½-teaspoon of sodium bicarbonate in a separate part of the bag. 4. Measure 5 mL of phenol red solution and pour it into the bag trying to keep it separate from the other chemicals. 5. Squeeze as much air out of the bag as possible, seal the bag and mix the contents. Write your observations in the data table. 6. Procedure B Provide step-by-step procedures describing what you did in lab to test your hypothesis. In four or less sentences explain what you did in the lab. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. Data Table Table 1: Observations Observed Changes When all chemicals mixed Table 2: Mixture A1 A2 A3 A4 A5 A6 Substances Water + NaHCO3 Water + CaCl2 NaHCO3 + CaCl2 Phenol Red + CaCl2 Phenol Red + NaHCO3 NaHCO3 + Water + CaCl2 Observations Observations HCl (Temp) HCl (Litmus) HCl (Observations) Analysis: Describe in written form, what happened with each chemical combination you used. For example, “When we mixed sodium bicarbonate, calcium chloride and phenol red in water all together in one baggy, we observed that…” Use what you wrote in the data table to complete your analysis. When we mixed sodium bicarbonate, calcium chloride and phenol red (in water) all together in one baggy, we observed that When we only mixed and , we observed that When we only mixed and , we observed that When we only mixed and , we observed that When we only mixed and , we observed that When we only mixed and , we observed that When we only mixed observed that and and we Conclusions Write 4 short paragraphs including Paragraph 1: Restate your hypothesis and explain why your hypothesis is accepted or rejected. Use specific examples from your data. Paragraph 2: What was observed that may have caused the results to be different from what you expected. Explain any sources of error that may have affected results. Paragraph 3: Write your ideas for ways to improve this experiment or changes to make it better Paragraph 4: Use specific examples from your data to answer the question from the beginning of the lab.