Reactions in a Bag Purpose: The purpose of this experiment is to miss several chemicals in a plastic bag, observe evidence of a reaction, then try to determine which chemicals are responsible for the changes. Materials: o Calcium Chloride o Silicon Dioxide o Bromthymol blue solution o Zipper-close bag o 10 mL graduated cylinder o Sodium hydrogen carbonate o Plastic spoons Class Procedure: 1. Examine each of the materials provided. 2. Blindfold one of the lab partners.
This student should hold the bag during step 3. 3. Place one spoonful of each of the solids and 10 mL of the liquid in the zip-lock bag. Quickly zip the bag shut. Observe any evidence that a reaction takes place. Include the observations by both lab partners.
4. Devise an experiment to determine which combination of chemicals is responsible for each of the changes that occur. In other words, which material (s) could be left out and still have each change occur? You may use laboratory glassware for your experiment, but you must have your experimental design approved by the teacher before you start. Results: We observed many reactions in this experiment, such as the mixture of chemicals became warm and hot.
It also gave off gas causing the bag to expand. It bubbled, turned yellow, foamed and fizzed. Group Procedure: 1. Take one spoonful of calcium chloride and put it in the plastic bag and pour 10 mL of the blue solution, Bromthymol blue, and label the bag accordingly. 2.
Do the same for each chemical and record observations. 3. Combine Calcium Chloride and Silicon dioxide and pour one spoonful of each in the bag and pour 10 mL of the blue solution in it and record observations. 4. Do the same for the combination of Calcium Chloride and Sodium Hydrogen carbonate. Observe results.
5. Then do the Silicon Dioxide and Sodium Hydrogen Carbonate in a different bag, add 10 mL the blue solution and observe results. Our Results: Chemical (s) Predictions What Happened Calcium Chloride It will get cold It got hot Silicon Dioxide It will get warm It did not mix in, separation evident Sodium Hydrogen Carbonate It will bubble It got cold, turned light blue Calcium Chloride And Silicon Dioxide It was a Cold and warm mixture. It got hot, the silicon dioxide still doesn't mix in Calcium Chloride And Sodium Hydrogen Carbonate It was cold, bubbly.
IT turns white and yellow, warm and cold. It bubbled, foamed and fizzed. Silicon Dioxide And Sodium Hydrogen Carbonate It got bubbly and warm It got cold, and the silicon did not mix in. Conclusion: Through our experiment we were able to identity the specific reactions of the individual chemicals. We found out that when calcium chloride was added it made it hot and gave off gas.
Silicon Dioxide added nothing to the mixture, and would not mix in. Sodium Hydrogen Carbonate, when added, made the mixture cold. In conclusion, we found that every chemical and their combinations caused different reactions causing different products. Questions: 1. List 5 types of evidence for a chemical reaction. Which did you observe in this experiment? 2.
Matter is not created nor destroyed. Also, no element changes into a different element in a chemical reaction. How then are new substances with new properties produced in chemical reactions? New substances with new properties are produced in chemical reactions because different elements and chemicals mixed together form a new substance. New substances are produced in chemicals reactions, but the chemicals do not change they are just mixed together.
In this experiment their reactions did not change they just differed on the various reactions of other elements that they were mixed with... 3. Were the observations you made qualitative or quantitative? Explain. The observations that we made were qualitative. They were qualitative because our observations pertained to quality; determining the nature of component parts. Qualitative observations rely more on your senses, rather than measuring tools..