1. Thermal chemistry is study of the transfer of heat in chemical reactions and physical changes. The student will be able to; 1. compare, contrast, analyze Potential Energy diagrams 2. interpret numerical heat values written in chemical reactions

2. Some reactions are: exothermic = get hot = released heat endothermic = get colder = absorbed heat The energy of the chemical reaction is displayed on a potential energy diagram.

3. Energy may be consumed or produced (exothermic or endothermic) in a chemical reaction. Enthalpy: change in energy delta H j/mol delta E j/mol enthalpy heat of reaction Activation Energy: E a the energy needed to get the reaction started

8. How is the height of the curve related to the ease a reaction will occur? What would the potential energy graph look like for a rapid reaction? What would happen if amount <E a were supplied?

9. Heat expressed in reactions. l.E- released H is negative, E- absorbed H is positive. 2.If H is + and written with products then exothermic 3C + Fe 2 O 3 3CO + 2Fe + 110.53 kj 3.If H is + and written with reactants then endothermic 2H 2 0(l) + 483.6 kj2H 2 (g) + O 2 (g) 4.If H is – and written with products then endothermic 3C + Fe 2 O 3 3CO + 2Fe – 110.53kj

10. Reaction Rate: “How fast the reaction proceeds” Reaction Rate depends on : 1. number of molecule collisions 2. efficiency of the collisions 5 factors can effect the rate of reaction: l. Nature of reactants 2. surface area ( big chunk vs. powder ) 3. temperature ( hot or cold ) 4. concentration 5. catalyst ( only effects rate does not participate in reaction…can recover.)

11. Thermal chemistry is study of the transfer of heat in chemical reactions and physical changes. The student will be able to; 1. compare, contrast, analyze Potential Energy diagrams 2. interpret numerical heat values written in chemical reactions

12. Entropy The student will : have a conceptual understanding of entropy and its application toward reactions. be able to determine the direction of entropy when given a chemical reaction.

13. Entropy: a measure of degree of randomness of the molecules. Delta S j/mol*K or kj/mol*K “most reactions in nature are toward disorder” Organized disorganized Entropy increases as phase change occurs from solid to liquid to gas SLgSLg Increase in entropy + delta S …..more crazy random (favored) Decrease in entropy - delta S ……more organized You can tell entropy by looking at the phases of the reaction ws. 17.8

17. Entropy The student will : have a conceptual understanding of entropy and its application toward reactions. be able to determine the direction of entropy when given a chemical reaction.