Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: First order phase transition (van der waals gas)

  1. Apr 19, 2010 #1
    1. The problem statement, all variables and given/known data
    Give the physical explanation of the graphs (Fig 4(a) and 4(b)) on Page 4
    http://www.pma.caltech.edu/~mcc/Ph127/b/Lecture3.pdf" [Broken]


    2. Relevant equations

    1) Why [tex]V_{g}[/tex] decreases with temperature but [tex]V_{l}[/tex] increases with temperature
    2) Why must phase transition happen at constant pressure (Maxwell construction)

    3. The attempt at a solution

    4(a) As temperature increases, greater proportion of molecules acquire sufficient energy to escape from liquid and consequently a higher pressure is needed to establish equilibrium between liquid and vapour

    4(b) don't really know how to explain
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Apr 22, 2010 #2
    Anyone who can help? please...
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook