GED SCIENCE LESSON 16 CHEMICAL REACTIONS Competency: Characterize the components of a chemical reaction. Learning Objectives: 1. Explain what happens during an exothermic and endothermic chemical reaction. 2. Distinguish between a balanced and unbalanced chemical reaction. Learning Activities: ___1. Read pgs. 174-181 Steck-Vaughn GED Science text and answer all the questions. ___2. Log on at http://www.myskillstutor.com and complete the Chemical Reactions and Matter exercises under Science I - Physical Sciences. ___3. Watch a movie about The Four Types of Chemical Reactions by Barbara Liang at the Wisconsin Online Resource Center. http://www.wisc-online.com/objects/index.asp?objD=AP13004 ___4. Study an animated pH scale at John Kyrk’s Website. http://www.johnkyrk.com/pH.html ___5. Write out the balanced chemical equation for photosynthesis indicating the reactants and products. ___6. Classify cellular respiration and photosynthesis as either endothermic or exothermic chemical reactions. ___7. Design your own chemical reaction and balance it using elements of your choice. ___8. Fill out the Chemical Equations worksheet located on the next page. 1 GED SCIENCE LESSON 16 Chemical Equations Worksheet Read about Chemical Equations in the GED reference text and use this activity to explore how to balance them. Parts of a Chemical Equation: Reactants C + (add energy) O (=) Products CO 2 1 atom Carbon 2 2 atoms Oxygen (1 molecule Oxygen) 1 molecule Carbon Dioxide (1 atom Carbon with 2 atoms Oxygen) 2C + 2O 2 CO 2 2 ( ) ( ) ( ) ( ) How many atoms of each element are on each side of the above chemical equation which shows 2 molecules of Carbon Dioxide? Fill in the ( ) above. Hint: The “big sized” numbers are coefficients and mean that the element atoms after it need to be multiplied by that number. Don’t forget to multiply in the “little sized” numbers too. Since matter cannot be created from nothing or destroyed into nowhere, the numbers of each element on one side of the arrow must equal the numbers on the other. If this is written correctly, the equation is considered balanced. Is the equation below balanced? What two life processes does it represent? 6CO2 + 6H2O + (light /energy) 2 C6H12O6 + 6O2