07-11-2012, 04:52 PM
Heat and Temperature
Heat and Temperature.ppt (Size: 1.14 MB / Downloads: 62)
Temperature
Temperature measures the “speed” of the molecules
Celsius Scale
00C water freezes, 1000C water boils
Fahrenheit Scale
320F water freezes, 2120F water boils
Kelvin Scale0K
2730K water freezes, 3730K water boils
ABSOLUTE Zero 00K
First Law of Thermodynamics
The first law of thermodynamics is the application of the conservation of energy principle to heat and thermodynamics
Enthalpy
Enthalpy is a quotient or description of thermodynamic potential of a system, which can be used to calculate the heat transfer
H = U(internal energy) + pV (pressure Volume)
The new variables often make the analysis of a system much simpler. For a gas, a useful additional state variable is the enthalpy which is defined to be the sum of the internal energy U plus the product of the pressure p and volume V. Using the symbol H for the enthalpy: .
Summary
Temperature is a measure of the activity of molecules.
Heat is a measure of energy
Specific Heat determines the amount of energy that a substance stores
Heat of Fusion or Vaporization is a measure of the energy stored in the physical state of matter