1. Conservation of Mass & Chemical Reactions 09.20 & 09.21 2012 Ms. Boon Chemistry

2. Catalyst

3. Objective I can explain the law of conservation of mass based on my laboratory observations and data.

4. Agenda Catalyst (10 min) & Debrief (5 min) Introduction to Chemical Reactions (15 min) Conservation Blows it Up! Lab Demonstration and Instructions (15 min) Conducting Laboratory Experiment (30 min) Lab Write Up (30 min) Exit Slip: Complete Lab Write Up

5. Introduction to Chemical Reactions What is a chemical reaction? http://www.youtube.com/watch?v=66kuhJkQCVM Video Focus Questions: The video shows the chemical reaction of iron and oxygen: 4 Fe (s) + 3 O 2 (g)  2 Fe 2 O 3 (s) 1. 1.What was the difference between the two reactions? Why was there a difference? Answer: The second reaction created more light/heat energy because there was more oxygen available.

6. Introduction to Chemical Reactions What is a chemical reaction? A chemical reaction is a process in which one or more substances change into one or more new substances. The chemical properties and physical properties of the new substances are different from those of the original substances. In a chemical reaction, the original substances, which can be elements or compounds, are known as reactants. The substances created are called products.

7. 3. What is a chemical equation? (answer on pp. 263) A chemical equation shows the chemical formulas and relative amounts of all the reactants and products that are part of a certain chemical reaction. sodium hydrogen bicarbonate + acetic acid  sodium acetate + carbon dioxide + water NaHCO 3 (s) + HC 2 H 3 O 2 (aq)  NaC 2 H 3 O 2 (aq) + CO 2 (g) + H 2 O (l) Reactants Products

8. Balanced Chemical Equations A chemical equation is “balanced” when there are the same number of atoms of each element on both sides of the arrow. NaHCO 3 (s) + HC 2 H 3 O 2 (aq)  NaC 2 H 3 O 2 (aq) + CO 2 (g) + H 2 O (l) Is it balanced? ReactantsProducts Na = 1 H = 5 C = 3 O = 5

9. Conservation Blows it Up! Please read the Lab introduction & Purpose silently (3 min) Summarize the Introduction and Purpose to your partner. Please read the materials & procedure silently (3 min) We will go over the materials and procedure together. Ms. Boon will demonstrate some of the steps.

10. Agenda Catalyst (10 min) & Debrief (5 min) Introduction to Chemical Reactions (15 min) Conservation Blows it Up! Lab Demonstration and Instructions (15 min) Conducting Laboratory Experiment (30 min) Lab Write Up (30 min) Exit Slip: Complete Lab Write Up

11. Homework Read pp. 267 – 270 Do problems: p. 269 #1-4. Answers on Pp. 275-285: Vocabulary! Write down the definitions and an example of the following: Combustion reaction Synthesis reaction Decomposition reaction Displacement reaction