Ch 9 Ppt

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Ch 9 Ppt
2013-01-27 23:57:55
CHM 112

Gases: Their Properties and Behavior
Show Answers:

  1. Gas mixtures are __ and __.
    • homogeneous
    • compressible
  2. Gases above us __ on us, causing __ affected by the __.
    • push down 
    • pressure
    • gravitational pull
  3. What is the typical tool for measuring pressure?
  4. What is the amount of mercury that goes in a barometer?
    760 mm
  5. In a barometer, as the pressure incresaes, what happens to mercury?
    As the pressure decreases, what happens to mercury?
    • pressure increses, mercury goes up; greater height
    • pressure decreases, mercury goes down; smaller height
  6. Ideal Gas
    a gas whose behavior follows the gas laws exactly; independent; a gas that doesn't interact with anything
  7. THe physical properties of a gas can be defined by four variables:
    • pressure
    • temp in K
    • volume
    • number of moles
  8. What is the formula for the Combined Gas Law?
  9. Another name for Boyle's Law?
    Relationship between volume and pressure?
    • Pressure-Volume Law
    • inverse relationship
  10. Another name for Charles' Law?
    Relationship between volume and temperature?
    • Temperature- Volume Law
    • directly proportional
  11. Significance of absolute zero?
    no motion
  12. Formula for:
    Boyle's Law
  13. Formula for:
    Charles' Law
  14. Formula for:
    Avogadro's Law
  15. Ideal gases obey an equation incorporating the laws of __, __, and __. 
    The formula is:
    • Charles, Boyle, and Avogadro
    • PV=nRT
  16. Formula for:
    Density and Molar Mass Calculations
    d=mass/ volume= (n x M)/ V = (P x M)/ (R x T)
  17. You can calculate the __ or __ of a gas. The density of a gas is usually very __ under atmospheric conditions.
    • density
    • molar mass (M)
    • low
  18. In __, for a constant temperature and pressure, volume is __ to moles.
    • gas stoichiometry
    • proportional
  19. Mole Fraction
    • Xi= (ni)/(ntotal) or 
    • Xi= Pi/Ptotal
  20. Kinetic Molecular Theory:
    What does it present?
    physical properties of gases in terms of hte motion of individual molecules
  21. Postulates of Kinetic-Molecular Theory:
    A gas consists of tiny particles, either atoms or molecules, moving about at random
  22. Postulates of Kinetic-Molecular Theory
    The volume of hte particles themselves is negligible compared with the total volume of the gas; most of the volume of a gas is empty space
  23. Postulates of Kinetic-Molecular Theory
    The gas particles act independently of one another; there are no attractive or repulsive forces between them
  24. Postulates of Kinetic-Molecular Theory
    Collisions of the gas particles, either with other particles or with the walls of a container, are elastic (constant temp)
  25. Postulates of Kinetic-Molecular Theory
    The average kinetic energy of the gas particles is proportional to the Kelvin temperature of the sample
  26. What is Root-Mean-Square
    measure of the average molecular speed
  27. Diffusion
    mixing of different gases by random molecular motion and collision
  28. Effusion
    when gas molecules escape without collision, through a tiny hole into a vacuum
  29. Graham's Law
    rate of effusion is proportional to its rms speed
  30. Deviation results from assumptions about ideal gases. What are the two
    • molecules in gaseous state do exert any force, either attractive or repulsive on one another
    • Volume of the molecules is negligibly small compared with that of the container
  31. The volume of a real gas is __ than predicted by the ideal gas law.
  32. At lower pressure, the volume of the gas particles is __ compared to the total volume.
  33. At higher pressure, the volume of the gas particiles is __ to the total volume.
    more significant compared
  34. The volume ofa real gas at high pressure is __ than the ideal value.
  35. Attractive forces between particles become more important at __.
    higher pressures