1. STAAR Chemistry Review Topic: Energy TEKS 11 – The student understands the energy changes that occur in chemical reactions. 11A - E

2. Student Expectation (SE) 11A – understand energy and its forms, including kinetic, potential, chemical, and thermal energies;

3. INDEX CARD TIME! TITLE: Energy and its Forms FRONT: List each type of energy BACK: Describe each type of energy with an example

4. Mini-Review Types of Energy: 1.Kinetic - energy of motion 2.Potential – energy defined by position rather than motion 3.Chemical - potential energy of a chemical substance to undergo a reaction 4.Thermal – (also known as heat energy) determined by how active molecules are

5. Mini-Review Example Question: Energy is best described as the capacity to A. transfer heat B. do work C. cause a chemical reaction D. compress a spring

6. Mini-Review Example Question: Energy is best described as the capacity to A. transfer heat B. do work C. cause a chemical reaction D. compress a spring

7. Student Expectation (SE) 11B – understand the law of conservation of energy and the processes of heat transfer

8. INDEX CARD TIME! TITLE: Law of Energy Conservation FRONT: State the Law of Energy Conservation

9. Mini-Review Energy can neither be created nor destroyed. Although energy can be absorbed or released in a change, it is not destroyed or created. It simply assumes a different form, i.e., chemical energy becomes heat energy.

10. INDEX CARD TIME! TITLE: Energy Conversion FRONT: List the ways energy can be converted to other forms of energy BACK: Give an example of this kind of energy conversion

11. Mini-Review Examples: Chemical to Kinetic Energy: A battery powering a fan Potential to Kinetic Energy: A boulder breaking loose from a hillside and rolling down the hill Chemical to Thermal Energy: A piece of wood oxidizing (burning) Each type of energy can be converted to another type of energy.

12. Mini-Review Sample Question: An engine makes a car move because of the force generated by small explosions as gasoline is burned in air and produces carbon dioxide and water. Why isn’t the stored chemical energy converted completely into kinetic energy of the car’s motion? A. During the explosion reaction, some energy is lost to the surroundings as heat B. Some of the energy from the gasoline is destroyed during the process C. Because the car is so heavy, it takes extra energy to get started. D. Some energy is transferred from the surroundings to the car’s engine.

13. Mini-Review Sample Question: An engine makes a car move because of the force generated by small explosions as gasoline is burned in air and produces carbon dioxide and water. Why isn’t the stored chemical energy converted completely into kinetic energy of the car’s motion? A. During the explosion reaction, some energy is lost to the surroundings as heat B. Some of the energy from the gasoline is destroyed during the process C. Because the car is so heavy, it takes extra energy to get started. D. Some energy is transferred from the surroundings to the car’s engine.

14. INDEX CARD TIME! TITLE: Heat Transfer FRONT: List the different ways heat can be transferred from one object to another BACK: Give an example of each of these energy transfer methods

15. Mini-Review Transferred by 1.Conduction – heat energy transferred through direct contact 2.Convection – heat energy transferred by movement of fluids 3.Radiation – heat energy transferred by waves

16. Student Expectation (SE) 11C – use thermochemical equations to calculate energy changes that occur in chemical reactions and classify reactions as exothermic or endothermic

17. INDEX CARD TIME! TITLE: Energy Change (Change in Enthalpy) FRONT: Define Exothermic and Endothermic Define the different enthalpies (heat of reaction, heat of combustion, heat of solution) BACK: Show samples of thermal- chemical calculations of chemical equations and determine if they are exothermic or endothermic

18. Mini-Review Definitions: Exothermic: A reaction in which heat is released. Usually the more exothermic a reaction is, the more stable the products are. Endothermic: A reaction in which heat is absorbed.

19. Mini-Review Definitions: Enthalpy Change: The amount of energy absorbed or lost by a system during a process at constant pressure Heat of Reaction: The amount of energy released or absorbed as heat during a chemical reaction.

20. Mini-Review Definitions: Heat of Combustion: Energy released as heat by the complete combustion of one mole of a substance Heat of Solution: The net amount of energy absorbed or released as heat when a specific amount of solute dissolves in a solvent

21. Mini-Review If is negative, reaction is exothermic and usually stable products formed If is positive, reaction is endothermic.

22. Mini-Review Sample Question: What is the estimated for this thermo- chemical equation? 2H (g) + O (g) 2H O(g) = ? A.488 kD B.-922 kD C.442 kJ D.-488 kJ 2 22

23. Mini-Review Sample Question: What is the estimated for this thermo- chemical equation? 2H (g) + O (g) 2H O(g) = ? A.488 kD B.-922 kD C.442 kJ D.-488 kJ 2 22

24. Student Expectation (SE) 11D – perform calculations involving heat, mass, temperature change, and specific heat

25. INDEX CARD TIME! TITLE: Specific Heat FRONT: Define what specific heat is and give the specific heat equation BACK: Show example calculations for specific heat equations

26. Mini-Review Specific heat is the amount of heat energy required to raise the temperature of one gram of substance by one Celsius degree or one Kelvin degree

27. Mini-Review Sample Question: How much energy must be added to 50.0 g of Water to raise its temperature from 40.0 C to 45.0 C? A.1045 joules B.50 joules C.1500 joules D.41.8 joules 0 0

28. Mini-Review Sample Question: How much energy must be added to 50.0 g of Water to raise its temperature from 40.0 C to 45.0 C? A.1045 joules B.50 joules C.1500 joules D.41.8 joules 0 0

29. Student Expectation (SE) 11E – use calorimetry to calculate the heat of a chemical process

30. INDEX CARD TIME! TITLE: Calorimetry FRONT: Draw a simple calorimeter BACK: Calculate the change in heat of a reaction given the data collected from calorimeter

31. Mini-Review A simple calorimeter will allow you to find the temperature change when an object of known mass is that is heated is submerged in water. The specific heat equation is then used to determine the unknown quantity (mass or energy) given the specific heat of the substance.

32. Mini-Review If necessary, what you need to know to combine these processes to find answers: -Know the chemical equation -Know the energy required for the reaction (specific heat equation) -Calculate heat per mole (may need to use atomic weight) - Calculate the enthalpy change ( )