ability -Energy-the to do work or move an object against a force. -Heat-that which flows from a hot body to a cold body -Temperature determines the direction of heat flow; always from higher T to lower T. -Molecular and atomic motion; heat energy is random, molecular and atomic motion. -10 g at 20degrees plus 10 g at 30 degrees>20 g at 25 degrees -types of molecular and atomic motion -Vibration: movement back and forth along an axis-This motion is excited by infrared radiation. -Rotation: movement round an axis-mode of molecular motion is excited by microwave radiation -Translation: movement from pt. A to pt. B -Kinetic Energy = (mv2)
-measuring energy-calorie (cal) is defined as the amount of energy required to raise the temperature of 1.0 g of water (at 0oC) by 1oC -A nutritional Calorie (Cal), also called a kilo-Calorie (kcal), is 1000 calories -.239cal/1.0J---4.18J/1.0cal---.239Cal/1.0kJ -If one uses kg for the mass and m/s for the velocity in the KE=1/2(mv2) formula, the answer has units of Joules; Thus, a Joule is 1 kg m2/s2 -fuel+O2>energy(heat-light)+products(carbon dioxide/water) -Energy is released because the potential energy of the reactants is greater than the potential energy of the products -1g of methane>6degree- 2000 cal/1degree=x cal/6 degree -E = CT-E=heat energy released in kJ or Cal-C=heat capacity of the calorimeter in kJ/degree or Cal/degree-T=increase in temp -44gC3H8/1mole C3H8=xgC3H8/5.68 moleC3H8 -heat of combustion-balance equation-determine required energy input/release-sum answers -photosynthesis-6co2+6h2o>c6h12o6+6o2 -coal-good-plentiful-bad-difficult/dangerous-hazardous byproducts-evironmentally destructive higher-easier -oil-good-energy60% to obtain-fewer byproducts-bad-combustion=nitrogen oxides, carbon dioxide-supply short-Middle East 65.3% -catalyst facilitates a reaction without being changed, or consumed by the reaction. -Entropy is a quantitative* measure of disorder or randomness -The second law of thermodynamics states that the entropy of the universe ALWAYS increases (J/K*mol) -Both heat energy and mechanical energy are forms of kinetic energy (energy of motion but heat energy is random-mechanical energy is ordered,directed -because of random nature of heat there is an inescapable limit to how efficiently it can be converted to work, or nonrandom energy -efficiency of a heat engine-%efficiency=high temp-low temp/high temp*100% (temp=K=degree+273) -Electron transfer involves movement of electrons from a locus (place) of high potential energy to a locus of low potential energy -as one moves from L>R across the chart-energy of outer level down-make electron work as moves to lower energy -batter-chem>electrical- Oxidation:Li Li+ + e- Reduction:F + e- F- Net Reaction:Li + F Li+ + F-oxidation-electrons on rite side-reduction-on left side -car batter- Oxidation: Pbo Pb2+ + 2e- Reduction: Pb4+ + 2e- Pb2+ - A fuel cell functions much like a battery except that it uses an external fuel supply - A photovoltaic cell converts light energy directly to electric energy - Unlike photovoltaic capture of solar energy, thermal solar energy works by concentrating sunlight on a pipe through which oil or water is flowing This heated fluid is used to generate electrical power in the usual way, i.e. turning a turbine/generator with high pressure steam.