Chemical Reactions 7.1 Chemical reactions alter arrangements of atoms. CHAPTER NEW CHAPTER Chemical Reactions the BIG idea Chemical reactions form new substances by breaking and making chemical bonds. 7.1 Chemical reactions alter arrangements of atoms. 7.2 The masses of reactants and products are equal. 7.3 Chemical reactions involve energy changes. 7.4 Life and industry depend on chemical reactions. CHAPTER OUTLINE CHAPTER RESOURCES

7.1 Chemical reactions alter arrangements of atoms. • Chemical changes occur through chemical reactions. • Evidence of a chemical reaction includes a color change, the formation of a precipitate, the formation of a gas, and a change in temperature. chemical reaction reactant product precipitate catalyst CHAPTER RESOURCES SECTION OUTLINE

7.1 Chemical reactions alter arrangements of atoms. • Chemical changes occur through chemical reactions. • Evidence of a chemical reaction includes a color change, the formation of a precipitate, the formation of a gas, and a change in temperature. chemical reaction reactant • Chemical reactions change reactants into products. product precipitate Reactants–bonds broken oxygen (O2) (CH4) methane + Products–new bonds formed carbon dioxide (CO2) (H2O) water catalyst CHAPTER RESOURCES SECTION OUTLINE

7.1 Chemical reactions alter arrangements of atoms. • Chemical changes occur through chemical reactions. • Evidence of a chemical reaction includes a color change, the formation of a precipitate, the formation of a gas, and a change in temperature. chemical reaction reactant • Chemical reactions change reactants into products. product precipitate catalyst VISUALIZATION Observe how changing the concentration of a reactant can change the rate of a reaction. CHAPTER RESOURCES SECTION OUTLINE

The masses of reactants and products are equal. 7.2 The masses of reactants and products are equal. • Mass is conserved in chemical reactions. • Chemical equations summarize chemical reactions. law of conservation of mass • Balanced chemical equations show the conservation of mass. coefficient CH4 O2 + 2O2 H O C CO2 H2O + 2H2O H O C CHAPTER RESOURCES SECTION OUTLINE

Chemical reactions involve energy changes. 7.3 Chemical reactions involve energy changes. • Different bonds contain different amounts of energy. • In an exothermic reaction, more energy is released than added. bond energy exothermic reaction • In an endothermic reaction, more energy is added than released. endothermic reaction Exothermic Reactions Bond Energy Products (energy released) Reactants (energy added) Endothermic Reactions Bond Energy Products (energy released) Reactants (energy added) photosynthesis CHAPTER RESOURCES SECTION OUTLINE

Chemical reactions involve energy changes. 7.3 Chemical reactions involve energy changes. • Different bonds contain different amounts of energy. • In an exothermic reaction, more energy is released than added. bond energy exothermic reaction • In an endothermic reaction, more energy is added than released. endothermic reaction VISUALIZATION View examples of endothermic and exothermic reactions. photosynthesis CHAPTER RESOURCES SECTION OUTLINE

Life and industry depend on chemical reactions. 7.4 Life and industry depend on chemical reactions. • Living things rely on chemical reactions that release energy from molecules. respiration Photosynthesis C6H12O6 + 6O2 6CO2 + 6H2O + energy Respiration C6H12O6 + 6O2 6CO2 + 6H2O + energy CHAPTER RESOURCES SECTION OUTLINE

Life and industry depend on chemical reactions. 7.4 Life and industry depend on chemical reactions. • Living things rely on chemical reactions that release energy from molecules. respiration • Different parts of modern society rely on chemical reactions. CHAPTER RESOURCES SECTION OUTLINE

7.1 Chemical reactions alter arrangements of atoms. I. Chemical reactions alter arrangements of atoms. chemical reaction A. Atoms interact in chemical reactions. 1. Physical Changes reactant 2. Chemical Changes product 3. Reactants and Products precipitate 4. Evidence of Chemical Reactions catalyst B. Chemical reactions can be classified. C. The rates of chemical reactions can vary. 1. Concentration 2. Surface Area CHAPTER RESOURCES 3. Temperature 4. Catalysts KEY CONCEPT SUMMARY

The masses of reactants and products are equal. 7.2 The masses of reactants and products are equal. II. The masses of reactants and products are equal. law of conservation of mass A. Careful observations led to the discovery of the conservation of mass. coefficient B. Chemical reactions can be described by chemical equations. C. Chemical equations must be balanced. 1. Balancing Chemical Equations 2. Using Coefficients to Balance Equations 3. Using the Conservation of Mass CHAPTER RESOURCES KEY CONCEPT SUMMARY

Chemical reactions involve energy changes. 7.3 Chemical reactions involve energy changes. III. Chemical reactions involve energy changes. bond energy A. Chemical reactions release or absorb energy. exothermic reaction B. Exothermic reactions release energy. endothermic reaction C. Endothermic reactions absorb energy. D. Exothermic and endothermic reactions work together to supply energy. photosynthesis CHAPTER RESOURCES KEY CONCEPT SUMMARY

Life and industry depend on chemical reactions. 7.4 Life and industry depend on chemical reactions. IV. Life and industry depend on chemical reactions. respiration A. Living things require chemical reactions. B. Chemical reactions are used in technology. C. Industry uses chemical reactions to make useful products. CHAPTER RESOURCES KEY CONCEPT SUMMARY

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