Slide 1

Physical Science December 7, 2011 Ms Cilli Pages 206-209 Slide 2 Slide 3 Describe the energy changes that take place during chemical reactions. Classify chemical reactions as exothermic or endothermic. Explain how energy is conserved during chemical reactions. Slide 4 C 3 H 8 + 5O 2 3CO 2 + 4H 2 O Slide 5 Chemical Energy: Chemical reactions involve the ________ of bonds in the reactants and the ________ of bonds in the products. Slide 6 Breaking bondsForming Bonds Slide 7 Slide 8 Is heat lost or gained? 1. A plastic bottle of water is placed in a freezer. After several hours, the water has frozen solid. 2. A chef places a stick of solid butter in a saucepan, and heats the saucepan over low heat on a stove. After several minutes, the stick of butter has melted. Slide 9 Exothermic: Endothermic: Slide 10 1. A plastic bottle of water is placed in a freezer. After several hours, the water has frozen solid. 2. A chef places a stick of solid butter in a saucepan, and heats the saucepan over low heat on a stove. After several minutes, the stick of butter has melted. 1. A plastic bottle of water is placed in a freezer. After several hours, the water has frozen solid. 2. A chef places a stick of solid butter in a saucepan, and heats the saucepan over low heat on a stove. After several minutes, the stick of butter has melted. Slide 11 Slide 12 Heat is on the _____ side Slide 13 Slide 14 Slide 15 All together now Slide 16 Is it endothermic or exothermic? (Look and ask yourself what side the heat is on) C 3 H 8 + 5O 2 3CO 2 + 4H 2 O + 2220kJ 2HgO + 181.7 kJ 2Hg + O 2 Is it endothermic or exothermic? (Look and ask yourself what side the heat is on) C 3 H 8 + 5O 2 3CO 2 + 4H 2 O + 2220kJ 2HgO + 181.7 kJ 2Hg + O 2 Slide 17 Which one is not one of the 5 types of chemical reactions? a.synthesis b.decomposition c.single-replacement d.double-replacement e.All of these are chemical reactions Which one is not one of the 5 types of chemical reactions? a.synthesis b.decomposition c.single-replacement d.double-replacement e.All of these are chemical reactions Slide 18 Independent Practice: Read section 7.3 Work on the study guide Homework: Complete the section 7.3 HW Due Thursday, December 8 by 8PM