Activity #25 Conservation of Mass

Activity 25: Conservation of Mass White Space ?: After looking at the two containers, which one do you think is a closed system and which is an open system? Why? Challenge Question: How does the total mass of the reactants compare to the total mass of the products in a chemical reaction? Background: Read p 64 and write down two facts. Vocabulary: Closed System: A chemical reaction that occurs in a container that does not allow reactants or products to escape. Open System: A chemical reaction that occurs in such a way that reactants or products are allowed to escape. Products: In a chemical reaction, the substance that are produced by the reactants; that is, the final substance that are present at the end.

Activity 25: Conservation of Mass Vocabulary Continued: Reactants: The original substances that are present at the beginning of a reaction. Conservation of Mass: Mass is neither created nor destroyed during a chemical reaction. Exothermic: A chemical reaction characterized by the production and release of heat.

Activity 25: Conservation of Mass Materials: Read over the list on B-65 Procedure: Read p B65 and B66 and write down what questions you have about the lab. Data: Use the “Mass of Reactants and Products” worksheet. Safety Precautions: Do NOT place the cap down on the tabletop. Keep goggles on at ALL times. Dispose of products in appropriate spot. Do NOT allow solutions to touch skin or clothing. If there is a spill of accidental contact occurs, let your teacher know ASAP!!!!!!!

Activity 25: Conservation of Mass Analysis Questions: On page B-67 answer questions #1a, 1b, 2, and 3. Conclusion: What did you learn about mass before and after an experiment? Notes to Self: Unit B test is Wednesday, December 19th.