General chemistry 3 Thermodynamics.txt

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General chemistry 3 Thermodynamics.txt
2013-09-09 18:27:05
General chemistry Thermodynamics

General chemistry 3 Thermodynamics.txt
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    • fileName "General chemistry 3 Thermodynamics"
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    • Def thermodynamics
    • The study of how energy effects a macroscopic system
  1. Define a state function and give rule for determining extensive vs intensive properties. How many state properties are needed to define a system state. How are extensive and intensive properties related
    • State function: any 3 states that define a system. One must be extensive
    • Rule: imagine an exact duplicate of a system. Then add them together. If the property changes, it is extensive
    • 3 state fxns will define any system
    • Extensive/extensive=intensive. ie density=mass/vol
  2. How to intuitively understand heat flow
    Imagine it is fluid
  3. What is chemical work, and what is the equation
    • Pressure volume work
    • W=PΔV pressure must be constant
  4. How to think of a heat engine
    Think of fluid because it is heat. Then compare to a concentration gradient. Heat flows from hot to cold and can do work. Cold heat must have work done on it to move from cold to hot
  5. What are the 7 thermodynamic state functions
    • Remember Gibb Has to Pee S T U V
    • 1: Gibbs free energy
    • 2: Enthalpy
    • 3: Pressure
    • 4: Enthalpy
    • 5: Temperature
    • 6: Internal Energy (U)
    • 7: Volume
  6. What are the 6 types of internal energy, which ones are in the sub category Thermal Energy
    • 1: rotational
    • 2: Translational
    • 3: Vibrational
    • 4: Intermolecular Potential
    • 5: Electronic
    • 6: Great Mass
    • Thermal Energy: 1-3
  7. What is the average kinetic energy of any fluid
  8. Define Enthalpy. Define Change in Enthalpy
    • H=U+PV
    • ΔH=ΔU+ΔPV p must be constant
  9. Define a standard state and standard Enthalpy of Formation
    • Standard state: the reference enthalpy value of 0 for any substance. A substance exists in this state at 1 Barr and some specific temp.
    • Standard Enthalpy of Formation: the change in H for a rxn that creates 1 mole of a compound from raw elements in their standard state
  10. Define Hess's Law and what negative and positive values mean
    • ΔH(rxn)=ΔH(products)-ΔH(reactants)
    • -ΔH= exothermic/spontaneous
    • +ΔH= endothermic/nonspontaneous
  11. Give entropy and Gibbs free energy equation
    • ΔS(universe)=ΔS(system)+ΔS(surroundings)
    • ΔG=ΔH-TΔS (-ΔG is a spontaneous reaction)