Thermodynamics: Chapter Eight

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Thermodynamics: Chapter Eight
2012-12-02 23:02:55

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  1. What is energy?
    the capacity to do work, or supply heat
  2. What is the formula for energy?
    Delta Energy= work + heat
  3. What is kinetic energy?
    energy of motion
  4. What is potential energy?
    stored energy
  5. What is thermal energy?
    the kinetic energy of molecular motion (translational, rotational, and vibrational)
  6. Thermal energy is proportional to __
    the temperature in degrees Kelvin
  7. What is heat?
    the amount of thermal energy transferred between two objects at different temperatures
  8. In an experiemnt: Reactants and products are th e__; everything else is the __.
    • system
    • surroundings
  9. Energy flow from the system to the surroundings has a __ sign. (__)
    • negative
    • loss of energy
  10. Energy flow from surroundings to the system has a __ (__)
    • positive 
    • gain of energy
  11. Open system
    Closed System
    Isolated System
    • matter or energy can be exchanged
    • only energy can be lost or gained
    • no matter or energy is exchanged
  12. What is the law of conservation of energy?
    The energy of an __ system must be __>
    • energy cannot be created or destroyed
    • isolated
    • constant
  13. The energy change in a system equals __
    • the work done on the system plus the heat added
    • DeltaE= q+w, where q= heat and w= work
  14. A reaction that combines something with oxygen is called?
  15. What is pressure? What is it measured by?
    • Force per unit area
    • Pascals or 1 atmospheric unit (atm)
  16. What is work?
    • force that produces an object's movement, times the distance moved 
    • Work = Force x Distance
  17. Work done by a system is __.
    Work done on a ssystem is __.
    negative positive
  18. I L atm= __ Joules?
  19. What is a state function?
    a function or property whose value depends only on the present state (condition) of the system
  20. The change in a __ is __ when the system returns to its original condition.
    • state function 
    • zero
  21. For __, the change is not __ if the path returns to its original condition.
    • nonstate functions 
    • zero
  22. The amount of heat exchanged between the system and the surroundigns is given the symbol __.
    What is the equation for it?
    At constant value (DeltaV=0): qv= __
    At constant pressure: qp= DeltaH
    • q
    • q= DeltaE + PDeltaV
  23. What is enthalpy?
    DeltaH is __
    • a state function whose value depends only on the current state of the system, not on the path taken to arrive at that state
    • enthalpy change or heat of reaction (at constant pressure)
  24. What is the Thermodynamic Standard State?
    most stable form of a substance at 1 atm pressure and at a specified temperature, usually 25 degrees C; 1 M concentration for all substances in solution
  25. What is enthalpy of Fusion DeltaHfusion?
    the amount of heat necessary to melt a substance without changing its temperature
  26. What is enthalpy of vaporization (DeltaHvap)
    The amount of heat required to vaporize a substance without changing its temperature
  27. What is enthalpy of sublimation (DeltaHsubl)?
    the amount of heat required to convert a substance from a solid to a gaas without going through a liquid phase
  28. Enthalpies of chemical change are often called __.
    heats of reaction (DeltaHreaction)
  29. What is endothermic?
    • endo: heat flows into the system from the surroundings and DeltaH has a positive sign
    • exo: heat flows out of the system into the surroundings and DeltaH has a negative sign
  30. What does reversing a reaction do to DeltaH?
    changes the sign (multiply by -1)