1. Do Now: Check Homework #1-8 (omit 2 & 6), 11a, 12 (p. 483) 1a) coal 8.2% crude oil 35.2% natural gas 43.5% natural gas liquids 4.0% primary electricity, hydroelectricity & nuclear 9.0% 1b) Pie chart-Compare with classmate. 3) total industrial 30.4% total transportation 29.5% agricultural 2.8% residential 17.7% public administration 1.7% commercial & other institutional 17.9%

2. 4 & 5) Compare line graphs with a classmate. 7) Gasoline, gasohol, fuel cells, gasoline-electrical hybrids, biodiesel, natural gas 8) Natural gas, oil, solar heating, wind 11a) Oil, gas, solar, wood, & solar energy all can be traced to the sun. Geothermal & nuclear energy originate from the formation of Earth. 12a) Coal, fuel oil, or natural gas can be burned to produce steam. 12b) Biomass, solar, wind, geothermal, & nuclear.

3. The Plan Section 11.2- Calorimetry Thermal Energy Calculations http://www.slideshare.net/lurganbeach/lesson-enthalpy-and-calorimetry

4. The study of energy changes by a chemical system during a chemical reaction is called thermochemistry. Cal orimetry is the technological process of measuring energy changes of an isolated system called a calorimeter.

5. Coffee Cup Calorimetry Essentially a polystyrene (Styrofoam) cup with a lid. The cup is partially filled with a known volume of water. Thermometer is inserted through the lid of the cup.

6. "Bomb" Calorimeter O2O2 O2O2 O2O2 thermometer "bomb" with ignition coil insulation motorized stirrer water

7. Assumptions When Using the Calorimetry Technique: All the energy lost or gained by the chemical system is gained or lost by the calorimeter; the system is isolated. All the material of the system is conserved. The specific heat capacity of water over the temperature range is 4.19 J/(g∙˚C).

8. The specific heat capacity of dilute solutions is 4.19 J/(g∙˚C). The density of a dilute solution is the same as that of water: 1.00g/mL. The thermal energy gained or lost by the rest of the calorimeter (other than water) is negligible (the container, lid, thermometer, stirrer do not gain or lose thermal energy.

9. Heat Transfer and Enthalpy Change First Law of Thermodynamics: energy can be converted from one form to another, but cannot be created or destroyed. Second Law of Thermodynamics: energy flows from where there is a lot to where there is less.

10. Analyzing Energy Changes Thermal energy is the total kinetic energy of the entities of a substance. Heat refers to the form of energy that is transferred from an object at a higher temperature to an object at a lower temperature. Q = mcΔt Q = quantity of thermal energy (J) m = mass (g) c = specific heat capacity (J/g·°C) Δt = temperature change (°C) The S.I. unit for energy (work) is the joule (J).

11. The specific heat capacity of a substance is the quantity of energy required to raise one gram of a substance by one degree Celsius. The change in temperature of the water is used to determine the quantity of heat energy released or absorbed by the chemical system.

13. Heat Transfer & Enthalpy Change Kinetic energy (energy of motions) of a chemical system includes: Moving electrons within atoms. The vibration of atoms connected by chemical bonds. The rotation & translation of molecules that are made up of these atoms. The temperature of a chemical system is a measure of the average kinetic energy of the entities that make it up. So a change in temperature means a change in kinetic energy.

14. Potential energy (stored energy in chemical bonds) includes: Covalent and/or ionic bonds between the entities (intramolecular). Intermolecular forces between entities. covalent bonding hydrogen bonding

15. The enthalpy (H) of a system is the sum of the kinetic and potential energy within it. WE CANNOT MEASURE ENTHALPY DIRECTLY! We can calculate the quantity of heat that is released or absorbed by the surroundings of a chemical system by measuring a change in temperature of the surroundings. ΔH = H products – H reactants An enthalpy change, ΔH, is the difference between the enthalpy of the products and the enthalpy of the reactants for a system under constant pressure. ΔH = Q (system)(calorimeter)

16. The change in potential energy of the chemical system equals the change in kinetic energy of the surroundings. Zn(s) + 2 HCl(aq) → H 2 (g) + ZnCl 2 (aq)

18. For an exothermic reaction (chemical system releases heat), ΔH (the enthalpy change) is negative. The temperature of the water increases. For an endothermic reaction (chemical system absorbs heat), ΔH (the enthalpy change) is positive. The temperature of the water decreases.

20. Molar Enthalpies & Calorimetry Enthalpy of reaction (or enthalpy change of reaction) refers to the energy change for a whole chemical system when reactants change to products. Δ r H = n Δ r H m Δ r H = enthalpy of reaction (kJ) n = chemical amount (mol) Δ r H m = molar enthalpy of reaction (kJ/mol) Molar enthalpy of reaction is the enthalpy change in a chemical system per mole of a specific chemical in a system at constant pressure.

21. The molar enthalpy of combustion of propane (producing water vapour) is –2 043.9 kJ/mol. p. 491

23. In a calorimeter, the change in enthalpy of the chemical system is equal to the change in thermal energy of the calorimeter. n Δ r H m = mcΔt ΔH = Q

24. p. 492

25. Read pgs. 485 – 493 pgs. 487, 492 Practice #’s 1 – 13 pg. 494 Section 11.2 Questions #’s 1 – 7