Ziplock Reaction LAB
I. Problem: What are some ways to determine if a chemical reaction has occurred?
II. Hypothesis:
III. Materials: Sodium bicarbonate (baking soda)
Red cabbage juice
Citric acid
Large Ziplock bag
Small Ziplock bag
IV. Procedure: 1. Put 4 grams of baking soda and 4 grams of citric acid into the LARGE Ziplock bag.
2. Measure and pour 50 mL of red cabbage juice into the SMALL Ziplock bag.
3. SEAL the SMALL bag and put it into the LARGE bag and seal. (AVOID trapping air into either bag!)
4. When the group is ready to observe, open the SMALL bag carefully inside the large bag WITHOUT unsealing the large bag. Turn the SMALL bag so that the liquid pours out and mixes with the powder.
5. Watch, listen, and feel the reaction happening inside the bag. Write down ALL observations (before, during, and after the reaction). BE SPECIFIC! – these are your results!
6. Clean-up lab area – RINSE /DRY both bags.
7. Write a lab write-up.
V. Results: (List of a of 10 observations- minimum!)
VI. Conclusion:
VII. Questions: 1. What was the first sign that a chemical reaction occurred?
2. What type of gas was released in this reaction?
3. Was this an endothermic or exothermic reaction?
4. Metric review: if this lab required you to measure the liquid in Liters, how many liters of cabbage juice is needed?
Background Information: The term “chemical reaction” is commonly used. Many reactions occur too quickly and too slowly for students to actually experience a chemical reaction conscientiously. Also, some reactions change appearance drastically and some subtly. Some reactions get warm and some get cold, and some are dangerous and some are safe. ALWAYS, one or more new products are formed. The following is a chemical equation for the above reaction:
C6H8O7 (s) + 3NaHCO3 (s)--- Na3C6H5O7 (aq) + 3H2O (l) + 3CO2 (g)