2.  Energy: ability to do work  Potential energy: stored energy  Kinetic energy: energy due to motion KE = ½ mv 2  Law of conservation of energy: Energy can neither be created or destroyed.  Work: Force acting over a distance  State function: A property of a system that changes independently of its pathway. Energy change is a state function whereas heat and work are not.

3.  Temperature: Average kinetic energy  Heat: Flow of energy due to a temperature difference. It is the total kinetic energy.  System: Part of the universe you are observing.  Surroundings include everything else in the universe.  Exothermic: energy flows out of the system  Endothermic: energy is absorbed from the surroundings.  In any exothermic reaction, some of the potential energy stored in the chemical bonds is converted to thermal energy as heat.  Heat flow into the surroundings (exothermic) LOWERS the potential energy.  What does an endothermic process do to the potential energy of a system?

4.  Internal energy: sum of the P.E. and the K.E. of a system. Δ E = q + w where q = heat and w = work  A calorie is the amount of energy it takes to raise 1 gram of a substance 1.0 o C.  1 calorie = 4.184 J  Specific heat capacity is the amount of energy needed to raise the temperature of 1 gram of a substance 1 degree Celsius. S.H. for liquid water is 4.184 J/g o C.  Q = m· c· Δ T OR J = g · Δ T · S.H.

5. Enthalpy: The amount of energy that is produced or absorbed in a given reaction. Δ H Calorimeter: A device used to determine the heat associated with a chemical reaction. Hess’s Law: In going from a particular set of reactants to a particular set of products, the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps. Entropy: a measure of disorder or randomness. Δ S

9. Law of Conservation of Energy: Energy can neither be created or destroyed. When we use energy, we degrade its usefulness and the quality of that energy is lowered. Concentrated energy (like gasoline) used to do work becomes energy that is spread out throughout the universe. Energy concerns are based on the quality, not the quantity of energy. The concept of the “heat death” of the universe addresses the eventuality that at some point in time all the energy will be spread evenly throughout the universe and thus will be at the same temperature. At this point, it would no longer to do any work and the universe will be “dead”.

10.  Sources of energy in our world include:  Wood  Coal  Petroleum: made of hydrocarbons  Gasoline, kerosene, diesel, heating oil, asphalt  Natural gas: primarily made of methane  Hydro: water  Nuclear  Solar