1. STAAR Ladder to Success Rung 9

2. Energy Defined as the ability to do work or produce heat Many forms – Light energy – Nuclear energy – Electrical energy – Heat energy**

3. ENERGY Kinetic Energy – motion of particles – related to temperature Potential Energy – stored energy – space between particles – related to phase changes

4. ENERGY Chemical Energy – energy from a chemical reaction Thermal Energy – heat

5. Law of Conservation of Energy During physical and chemical processes, energy may change from one form to another but it may not be created or destroyed. Also known as the First Law of Thermodynamics

6. Heat Transfer Conduction Convection Radiation

7. Enthalpy (H) The heat content of a system, or the amount of energy within a substance, both kinetic and potential. We refer to the change of enthalpy in chemistry. We may also refer to it as the heat of reaction.

8. Exothermic Reaction reaction that releases energy products have lower PE than reactants energy released

9. Endothermic Reaction reaction that absorbs energy reactants have lower PE than products energy absorbed

10. Example #1: Calculate the change in energy for the following reaction at standard conditions. Is the is reaction exothermic or endothermic?

11. Example #2: Calculate the change in energy for the following reaction. Is this reaction endothermic or exothermic?

12. Heat Capacity Specific Heat – energy required to raise the temp of 1 gram of a substance by 1°C – water has a very high heat capacity

13. Example #1: Calculate the heat absorbed by a 20 g piece of copper metal that is heated from 25  C to 125  C. The specific heat of copper is.385.

14. Example #2: The specific heat of water is 4.18. A 1200 g water sampel at 19  C loses 10,000 J of heat. What is the final temperature?