3ThermalChem.pdf - Chapter 5 Thermochemistry 5.1 Energy and...

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Chapter 5 Thermochemistry
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5.1 Energy and Power
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Combustion: turning chemical energy into heat
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Combustion: turning chemical energy into heat and turning heat into work. Welcome to the Industrial Age!
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Turning chemical energy into electricity
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5.2 The Nature of Energy What drives a chemical reaction?
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Energy Energy is the ability to do work or transfer heat. Energy used to cause an object that has mass to move is called work . Energy used to cause the temperature of an object to rise is called heat . Thermochemistry and T hermodynamics : thermo: heat dynamics: power
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Kinetic Energy Kinetic energy is energy an object possesses by virtue of its motion:
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Potential Energy Potential energy is energy an object possesses by virtue of its position or chemical composition. The most important form of potential energy in molecules is electrostatic potential energy, E el :
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Units of Energy The SI unit of energy is the joule ( J ) : An older, non-SI unit is still in widespread use, the calorie ( cal ) : 1 cal = 4.184 J (Note: this is not the same as the calorie of foods; the food calorie is 1 kcal!)
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Internal Combustion Engine
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Definitions: System and Surroundings The system includes the molecules we want to study (here, the hydrogen and oxygen molecules). The surroundings are everything else (here, the cylinder and piston).