1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Physical Chemistry- Using the integrated Vant Hoff Equation with K values.

  1. Sep 25, 2012 #1
    1. The problem statement, all variables and given/known data
    The equilibrium concentration of oxygen in fresh water exposed to the atmosphere is given for two temperatures. At 15 degrees celcius equilib [O2]= 630μmol/L at 25 degrees celcius equiln [O2]= 517μmol/L

    The expression for the equilibrium constant, K, between the oxygen in the gas phase and in solution is given by K=[O2]/PO2/atm. Where pO2 is the partial pressure of atmospheric oxygen.

    I need to calculate the enthalpy of dissolution, I figured I need to use the integrated Vant hoof equation.
    But how do I figure out the partial pressues of oxygen so I can calculate the equilibrium constants?

    [Thank you
     
  2. jcsd
  3. Sep 25, 2012 #2

    AGNuke

    User Avatar
    Gold Member

    Partial pressure of oxygen is the fraction of pressure exerted by atmospheric oxygen. And since the Partial pressure is not going to change whether the oxygen dissolves or not, you don't require the use of oxygen's partial pressure.

    You may write simply, K = [O2]. Now just use Van't Hoff's Equation.
     
  4. Sep 27, 2012 #3
    Thanks.

    I do not understand why I don't have to use the partial pressure, when it is in the expression for Kp. Is this the case for any equilibrium constant involving kp=[x]/Po2/atm?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Physical Chemistry- Using the integrated Vant Hoff Equation with K values.
  1. K value (Replies: 5)

Loading...