Chemistry ch 17

  1. as the temp of a solid increases, so does the
    velocity of the particles
  2. melting point
    the point at which particles slip out of their organized pattern and the solid becomes a liquid
  3. freezing point
    the point at which the particles of the liquid move so slowly that they move back into an organized pattern
  4. When does MP = FP?
    at the same pressure
  5. at some temperature, liquid particles move so fast that they escape the surface to form
  6. equilibrium
    • the state in which 2 opposing processes occur at an equal rate
    • requires a closed system
  7. dynamic equilibrium
    particles are constantly moving from or returning to liquid
  8. saturated
    when a liquid is in equilibrium qith the vapor above it
  9. the higher the temperature, the higher the
  10. Le Chatelier's Principle
    • when a system in equilibrium os subjected to a change (stress), the system will react to relieve the stress
    • change in temperature
    • pressure
    • concentration
  11. vapor pressure
    the pressure generated by a vapor that is in equilibrium with a liquid
  12. substances with low vapor pressures have what kind of intermolecular forces?
    strong- hold particles tightly
  13. substances with high vapor pressures have what kind of intermolecular forces?
    weak- hold particles weakly
  14. melting point of gas
    the temp at which the vp of the solid and the vp of the liquid are equal
  15. sublimation
    • solids that vaporize quickly in air without going through the liquid phase
    • dry ice, moth balls
  16. when heated, vp and ke
  17. what happens when the vp and ke of a liquid increase?
    the molecules get pushed further apart, bubbles of vapor form and move to the surface
  18. Normal BP
    when the vp in a system is equal to the standard atmospheric pressure (101.3 kPa)
  19. difference between evaporation and boiling
    evaporation is at the surface, boiling is throughout
  20. volatile
    • liquid boils at low temp and evaporates quickly at room temp
    • ethyl alcohol
    • ether
  21. non-volatile
    • boil at high temp and evaporate slowly
    • molasses
  22. what kind of vp's do volatile liquids have?
    high vp
  23. liquefaction
    condensing substances that are normally gases at room temp to liquids- involves temp and pressure
  24. critical temperature
    • Tc
    • temp above which no amount of pressure will result in the liquification of a gas
  25. critical pressure
    • Pc
    • the pressure that will cause a gas to liquefy at Tc
  26. Low Tc indicates
    weak forces between molecules
  27. high Tc indicates
    strong forces between molecules
  28. phase diagram
    shows the relationship between pressure, temp, and physical state
  29. triple point
    the temp and pressure at which all 3 phases are at equilibrium
  30. when energy is added to a solid, the temp increases until
    Tm is reached
  31. the temp of a melting solid doesn't change until
    all of the solid is completely melted
  32. the energy added to melt it is needed to change
    • the positions of the particles
    • PE increases
  33. Enthalpy of fusion
    energy required to melt 1 gram of a specific substance at its Tm
  34. ^Hfus of ice
    334 j/g
  35. Enthalpy of vaporization
    energy required to vaporize 1 gram at its Tb
  36. ^Hvap of water
    2260 j/g
  37. melting and boiling points for molecules can predicted with a knowledge of
    the atomic and molecular structure
  38. when the molecules contain H and it's covalently bonded to a highly electronegative atoms, it forms
    a highly polar molecule
  39. Hydrogen bonding forms an
    extremely strong type of dipole
  40. Hydrogen strongly bonds with... and forms
    • N, O, and F
    • NH3
    • H2O
    • HF
  41. water has what kind of density
    most- 3.98 deg C
  42. what breaks the hydrogen bonds?
  43. what do the clusters of hydrogen bonds make?
    crystalline structure with many open spaces
  44. what is surface tension caused by?
    unbalanced forces on the surface particles of a liquid
  45. is surface tension high or low for water?
    very high
  46. is surface tension high or low for mecury?
    very low
Card Set
Chemistry ch 17
chapter 17, Liquids